JSFiddle - React, Tailwind, and code Playground
HTML
<form>
<table>
<tr><td><input type="text" value="50" name="myvar[]" /></td></tr>
<!-- This button will clone the previous set of form elements -->
<tr><input type="button" value="Add New Line" onclick="this.getParent('tr').getPrevious('tr').clone().inject(this.getParent('tr'), 'before')" /></tr>
</table>
</form>