JSFiddle - React, Tailwind, and code Playground

HTML

<ul class="elements">
    <li>
        <span>Span 1</span>
        <span>Span 2</span>
        <span>Span 3</span>
    </li>
    <li>
        <span>Span 4</span>
        <span>Span 5</span>
        <span>Span 6</span>
    </li>
</ul>
<a href="#" class="new_row">Add new row</a>
<a href="#" class="new_column">Add new column</a>

JavaScript

$('.new_row').click( function(e) {
    e.preventDefault();
	var ul = $(this).prev('.elements');
        
	var new_data= $("li", ul).eq(0).clone();
	new_data.appendTo(ul);
});
$('.new_column').click( function(e) {
    e.preventDefault();
    $('li').each(function(){
        $('span:last').clone();
    });
});