JSFiddle - React, Tailwind, and code Playground

@author Roman Grinyov <w3lifer@gmail.com>

HTML

<table>
  <tbody>
    <tr>
    <td></td>
    <td></td>
    <td></td>
  </tr>
  <tr>
    <td></td>
    <td></td>
    <td></td>
  </tr>
  </tbody>
</table>
<br>
<button>Add row</button>

CSS

table {
  border: 1px solid #000;
  border-spacing: 10px;
}

td {
  border: 1px solid #000;
  height: 50px;
  width: 50px;
}

tr:nth-child(n + 3) {
  position: relative;
}

tr:nth-child(n + 3)::after {
  color: #f00;
  content: '×';
  display: block;
  font-weight: bold;
  height: 10px;
  width: 10px;
  position: absolute;
  top: 30%;
  right: -3%;
}

JavaScript

const tbody = document.querySelector('tbody');

document.querySelector('button').addEventListener('click', event => {
  const tr = tbody.querySelector('tr:last-child').cloneNode(true);
  tbody.appendChild(tr);
});