JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr>
        <td>
            <div>
            </div>
        </td>
    </tr>
</table>

CSS

tr { height:300px; }
td { position:relative; }
div { 
    width:10px;
    position:absolute;
    top:10px; bottom:10px;
    background:grey
}