To add rows to a table with JavaScript, use the DOM method insertRow().
Example
You can try to run the following code to learn how to add a row to a table one at a time −
<!DOCTYPE html>
<html>
<head>
<script>
function rowFunction(x) {
var a = document.getElementById(x).insertRow(0);
var b = a.insertCell(0);
var c = a.insertCell(1);
b.innerHTML = c.innerHTML = "row";
}
</script>
</head>
<body>
<table style="border:2px solid black" id="newtable">
<tr>
<td>One</td>
<td>Two</td>
</tr>
<tr>
<td>Three</td>
<td>Four</td>
</tr>
<tr>
<td>Five</td>
<td>Six</td>
</tr>
</table>
<p>
<input type="button" onclick="rowFunction('newtable')" value="Add a row">
</p>
</body>
</html>