您必须在循环内创建 td 和 text 节点。您的代码仅创建 2 个 td，因此只有 2 个可见。例子：

var table = document.createElement('table');
for (var i = 1; i < 4; i++){
    var tr = document.createElement('tr');   

    var td1 = document.createElement('td');
    var td2 = document.createElement('td');

    var text1 = document.createTextNode('Text1');
    var text2 = document.createTextNode('Text2');

    td1.appendChild(text1);
    td2.appendChild(text2);
    tr.appendChild(td1);
    tr.appendChild(td2);

    table.appendChild(tr);
}
document.body.appendChild(table);

这是因为您只创建了两个td元素和 2 个文本节点。

在循环中创建所有节点

在循环中重新创建节点：

var tablearea = document.getElementById('tablearea'),
    table = document.createElement('table');

for (var i = 1; i < 4; i++) {
    var tr = document.createElement('tr');

    tr.appendChild( document.createElement('td') );
    tr.appendChild( document.createElement('td') );

    tr.cells[0].appendChild( document.createTextNode('Text1') )
    tr.cells[1].appendChild( document.createTextNode('Text2') );

    table.appendChild(tr);
}

tablearea.appendChild(table);

创建然后在循环中克隆

预先创建它们，并在循环内克隆它们：

var tablearea = document.getElementById('tablearea'),
    table = document.createElement('table'),
    tr = document.createElement('tr');

tr.appendChild( document.createElement('td') );
tr.appendChild( document.createElement('td') );

tr.cells[0].appendChild( document.createTextNode('Text1') )
tr.cells[1].appendChild( document.createTextNode('Text2') );

for (var i = 1; i < 4; i++) {
    table.appendChild(tr.cloneNode( true ));
}

tablearea.appendChild(table);

带有文本字符串的表工厂

做一个表工厂：

function populateTable(table, rows, cells, content) {
    if (!table) table = document.createElement('table');
    for (var i = 0; i < rows; ++i) {
        var row = document.createElement('tr');
        for (var j = 0; j < cells; ++j) {
            row.appendChild(document.createElement('td'));
            row.cells[j].appendChild(document.createTextNode(content + (j + 1)));
        }
        table.appendChild(row);
    }
    return table;
}

并像这样使用它：

document.getElementById('tablearea')
        .appendChild( populateTable(null, 3, 2, "Text") );

带有文本字符串或回调的表工厂

工厂可以很容易地修改为接受一个函数以及第四个参数，以便以更动态的方式填充每个单元格的内容。

function populateTable(table, rows, cells, content) {
    var is_func = (typeof content === 'function');
    if (!table) table = document.createElement('table');
    for (var i = 0; i < rows; ++i) {
        var row = document.createElement('tr');
        for (var j = 0; j < cells; ++j) {
            row.appendChild(document.createElement('td'));
            var text = !is_func ? (content + '') : content(table, i, j);
            row.cells[j].appendChild(document.createTextNode(text));
        }
        table.appendChild(row);
    }
    return table;
}

像这样使用：

document.getElementById('tablearea')
        .appendChild(populateTable(null, 3, 2, function(t, r, c) {
                        return ' row: ' + r + ', cell: ' + c;
                     })
        );

您需要为每一列创建新的 TextNode 和 td 节点，而不是像您的代码那样在所有列中重用它们。

编辑：像这样修改你的代码：

for (var i = 1; i < 4; i++)
{
   tr[i] = document.createElement('tr');   
      var td1 = document.createElement('td');
      var td2 = document.createElement('td');
      td1.appendChild(document.createTextNode('Text1'));
      td2.appendChild(document.createTextNode('Text2'));
      tr[i].appendChild(td1);
      tr[i].appendChild(td2);
  table.appendChild(tr[i]);
}

<title>Registration Form</title>
<script>
    var table;

    function check() {
        debugger;
        var name = document.myForm.name.value;
        if (name == "" || name == null) {
            document.getElementById("span1").innerHTML = "Please enter the Name";
            document.myform.name.focus();
            document.getElementById("name").style.border = "2px solid red";
            return false;
        }
        else {
            document.getElementById("span1").innerHTML = "";
            document.getElementById("name").style.border = "2px solid green";
        }

        var age = document.myForm.age.value;
        var ageFormat = /^(([1][8-9])|([2-5][0-9])|(6[0]))$/gm;

        if (age == "" || age == null) {
            document.getElementById("span2").innerHTML = "Please provide Age";
            document.myForm.age.focus();
            document.getElementById("age").style.border = "2px solid red";
            return false;
        }
        else if (!ageFormat.test(age)) {
            document.getElementById("span2").innerHTML = "Age can't be leass than 18 and greater than 60";
            document.myForm.age.focus();
            document.getElementById("age").style.border = "2px solid red";
            return false;
        }
        else {
            document.getElementById("span2").innerHTML = "";
            document.getElementById("age").style.border = "2px solid green";
        }

        var password = document.myForm.password.value;
        if (document.myForm.password.length < 6) {
            alert("Error: Password must contain at least six characters!");
            document.myForm.password.focus();
            document.getElementById("password").style.border = "2px solid red";
            return false;
        }
        re = /[0-9]/g;
        if (!re.test(password)) {
            alert("Error: password must contain at least one number (0-9)!");
            document.myForm.password.focus();
            document.getElementById("password").style.border = "2px solid red";
            return false;
        }
        re = /[a-z]/g;
        if (!re.test(password)) {
            alert("Error: password must contain at least one lowercase letter (a-z)!");
            document.myForm.password.focus();
            document.getElementById("password").style.border = "2px solid red";
            return false;
        }
        re = /[A-Z]/g;
        if (!re.test(password)) {
            alert("Error: password must contain at least one uppercase letter (A-Z)!");
            document.myForm.password.focus();
            document.getElementById("password").style.border = "2px solid red";
            return false;
        }
        re = /[$&+,:;=?@#|'<>.^*()%!-]/g;
        if (!re.test(password)) {
            alert("Error: password must contain at least one special character!");
            document.myForm.password.focus();
            document.getElementById("password").style.border = "2px solid red";
            return false;
        }
        else {
            document.getElementById("span3").innerHTML = "";
            document.getElementById("password").style.border = "2px solid green";

        }

        if (document.getElementById("data") == null)
            createTable();
        else {
            appendRow();
        }
        return true;
    }






    function createTable() {

        var myTableDiv = document.getElementById("myTable");  //indiv
        table = document.createElement("TABLE");   //TABLE??
        table.setAttribute("id", "data");
        table.border = '1';
        myTableDiv.appendChild(table);  //appendChild() insert it in the document (table --> myTableDiv)
        debugger;

        var header = table.createTHead();

        var th0 = table.tHead.appendChild(document.createElement("th"));
        th0.innerHTML = "Name";
        var th1 = table.tHead.appendChild(document.createElement("th"));
        th1.innerHTML = "Age";


        appendRow();

    }

    function appendRow() {
        var name = document.myForm.name.value;
        var age = document.myForm.age.value;


        var rowCount = table.rows.length;
        var row = table.insertRow(rowCount);

        row.insertCell(0).innerHTML = name;
        row.insertCell(1).innerHTML = age;



        clearForm();


    }


    function clearForm() {
        debugger;

        document.myForm.name.value = "";
        document.myForm.password.value = "";
        document.myForm.age.value = "";



    }
    function restrictCharacters(evt) {

        evt = (evt) ? evt : window.event;
        var charCode = (evt.which) ? evt.which : evt.keyCode;
        if (((charCode >= '65') && (charCode <= '90')) || ((charCode >= '97') && (charCode <= '122')) || (charCode == '32')) {
            return true;
        }
        else {
            return false;
        }
    }

</script>



<div>
    <form name="myForm">

        <table id="tableid">

            <tr>
                <th>Name</th>
                <td>
                    <input type="text" name="name" placeholder="Name" id="name" onkeypress="return restrictCharacters(event);" /></td>
                <td><span id="span1"></span></td>
            </tr>

            <tr>
                <th>Age</th>

                <td>
                    <input type="text" onkeypress="return event.charCode === 0 || /\d/.test(String.fromCharCode(event.charCode));" placeholder="Age"
                        name="age" id="age" /></td>
                <td><span id="span2"></span></td>
            </tr>

            <tr>
                <th>Password</th>
                <td>
                    <input type="password" name="password" id="password" placeholder="Password" /></td>
                <td><span id="span3"></span></td>
            </tr>


            <tr>
                <td></td>
                <td>
                    <input type="button" value="Submit" onclick="check();" /></td>
                <td>
                    <input type="reset" name="Reset" /></td>
            </tr>

        </table>
    </form>

    <div id="myTable">
    </div>

</div>

var html = "";
    for (var i = 0; i < data.length; i++){
    html +="<tr>"+
            "<td>"+ (i+1) + "</td>"+
            "<td>"+ data[i].name + "</td>"+
            "<td>"+ data[i].number + "</td>"+
            "<td>"+ data[i].city + "</td>"+
            "<td>"+ data[i].hobby + "</td>"+
            "<td>"+ data[i].birthdate + "</td>"+"<td><button data-arrayIndex='"+ i +"' onclick='editData(this)'>Edit</button><button data-arrayIndex='"+ i +"' onclick='deleteData()'>Delete</button></td>"+"</tr>";
}
$("#tableHtml").html(html);