Setting table column width

I’ve got a simple table that is used for an inbox as follows:

<table border="1">
     <tr>
        <th>From</th>
        <th>Subject</th>
        <th>Date</th>
    </tr>
</table>

How do I set the width so the From and Date are 15% of the page width and the Subject is 70%. I also want the table to take up the whole page width.