JSFiddle - React, Tailwind, and code Playground

HTML

<table id="mytable">
    <thead>
        <tr>
            <th colspan=3>Values (Type A)</th>
        </tr>
        <tr>
            <th colspan=3>Values (Type B)</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>1</td><td>2</td><td>3</td>
        </tr>
        <tr>
            <td>4</td><td>5</td><td>6</td>
        </tr>
    </tbody>
</table>

CSS

th {
    background-color: #4072B4;
}
td {
    background-color: #608DC9
}

JavaScript

var mytable = document.querySelector('#mytable');
var clonedMyTable = mytable.cloneNode();
console.log(clonedMyTable);