JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <thead>
        <tr>
            <th colspan="2">Object</th>
            <th colspan="2">Openings</th>
            <th colspan="3">Internal Dimensions</th>
            <th colspan="3">Weight</th>
            <th>Volume</th>
        </tr>
        <tr>
            <th>sub header</th>
            <th>sub header</th>
            <th>sub header</th>
            <th>sub header</th>
            <th>sub header</th>
            <th>sub header</th>
            <th>sub header</th>
            <th>sub header</th>
            <th>sub header</th>
            <th>sub header</th>
            <th>sub header</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <th>header</th>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
        </tr>
        <tr>
            <th>header</th>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
        </tr>
         <tr>
            <th>header</th>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
        </tr>
             <tr>
            <th>header</th>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
            <td> </td>
        </tr>
    </tbody>
</table>

CSS

th, td {
    font-weight:normal;
    padding:5px;
    width:120px;
    vertical-align:top;
}
th {
    background:#00B0F0;
}
tr + tr th, tbody th {
    background:#DAEEF3;
}
tr + tr, tbody {
    text-align:left
}
table, th, td {
    border:solid 1px;
    border-collapse:collapse;
    table-layout:fixed;
}