JSFiddle - React, Tailwind, and code Playground

HTML

<table id="ct">
    <tbody>
    <tr id="list_items_11" class="list_item">
        <td>This Line</td>
        <td><input type="button" name="addNewArea" class="addNewArea button" value="+"/></td>
      </tr>
   </tbody>
</table>

JavaScript

$(document).on('click', '.addNewArea', function(event) {	
		var areaCount = $('#ct tbody tr').length;
		var newAreaLine = '<tr id="list_items_' + areaCount + '" class="list_item"><td>New Line</td><td><input type="button" name="addNewArea" class="addNewArea button" value="+" /></td></tr>';
		$(newAreaLine).appendTo('#ct tbody');
		$(this).remove();
	});