<!DOCTYPE html>
<html>
<head>
<title>Задание</title>
<meta charset="utf-8">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script type="text/javascript">
$(function(){
$('#add').click(add_row());
})
let num = 0;
function add_row(){
let test = document.getElementById("table");
let row = document.createElement('tr');
let colum = document.createElement('td');
let input_area = document.createElement('input');
input_area.type="text";
colum.appendChild(input_area);
row.appendChild(colum);
test.appendChild(row);
}
</script>
</head>
<body>
<div id="tab">
<table id = "table">
<th>№</th>
<th>Name</th>
<th>Value</th>
<th>Price</th>
<th>Sum</th>
<th>Operations</th>
</table>
</div>
<button type="button" id="add" >Добавить</button>
</body>
</html>
$(function(){
$('#add').click(function () {
add_row();
})