JSFiddle - React, Tailwind, and code Playground

HTML

<table class="table">
    <thead>
        <td>Col1</td>
        <td>Col2</td>
    </thead>
    <tbody>
        <tr>
            <td>Data</td>
            <td>More</td>
        </tr>
        <tr>
            <td>Example</td>
            <td>Stuff</td>
        </tr>
    </tbody>
</table>
<button class="btn addbutton">Add</button>

JavaScript

$(document).on('click', '.addbutton', function(e) {
    e.preventDefault();
    var $tr = $(this).prev('table').find('tbody>tr:last');
    $tr.clone(true).insertAfter($tr);
});