JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script>
<script>
function addfield() {
  n = $('table#t1 tr').length;
  $('table#t1').append('<tr><td><input name=field'+n+' ></td><td><input name=value'+n+'></td></tr>');
  $('input[name="field'+n+'"]').focus();
}
</script>

<table id=t1>
  <thead>
    <tr>
      <th>field</th>
      <th>value</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Bill</td>
      <td>[email protected]</td>
    </tr>
  </tbody>
</table>
<div><a onclick='addfield();return false;'>Add field</a></div>