<style>
    table {
        width: 600px;
        table-layout: fixed;
        border-collapse: collapse;
        border: 1px solid black;
    }

    td {
        border: 1px solid black;
    }
</style>

<table>
    <tr>
        <td style="width: 50px">cell</td>
        <td style="width: 50px">cell</td>
        <td style="width: 100px">A table cell</td>
        <td style="width: 300px">A table cell</td>
    </tr>
    <tr>
        <td>cell</td>
        <td>cell</td>
        <td>A table cell</td>
        <td>A table cell</td>
    </tr>
</table>