Fronton,
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<style type="text/css">
[name='1'] {
width: 40px;
}
</style>
<script>
function add() {
let nodet = document.createElement('tr');
let node = document.createElement('td');
node.innerHTML = "<input type='text' name='1'>";
document.getElementById('tabl').append(nodet);
for (let i = 0; i < 9; i++) nodet.appendChild(node.cloneNode(true));
}
</script>
</head>
<body>
<table id='tabl' border='1' align='left'><tr>
<th>1</th>
<th>2</th>
<th>3</th>
<th>4</th>
<th>5</th>
<th>6</th>
<th>7</th>
<th>8</th>
<th>9</th></tr>
<tr>
<td><input type='text' name='1'></td>
<td><input type='text' name='1'></td>
<td><input type='text' name='1'></td>
<td><input type='text' name='1'></td>
<td><input type='text' name='1'></td>
<td><input type='text' name='1'></td>
<td><input type='text' name='1'></td>
<td><input type='text' name='1'></td>
<td><input type='text' name='1'></td>
</tr>
</table>
<input type='button' value='Добавить новую строку' onClick='add();'>
</body>
</html>