JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr>
        <td>A</td>
        <td>B</td>
    </tr>
    <tr>
        <td>C</td>
        <td>D</td>
    </tr>
</table>

JavaScript

$('tr').each(function(){
    var self = $(this);
    self.after('<tr>').next().append( self.find('td:last') );
});