I recommend doing this with javascript. You could do it with images, but there's a big chance you won't get it to work as you'd wish. If you look into this solution, have a look at table-layout: fixed.
But, as I see it, doing this the easy way is the way to go. Among other things, making the whole table cells clickable is a feature enhancement which isn't needed for actual functionality, and as such you don't have to worry about non-script users.
<style>
td:hover {
cursor: pointer;
}
</style>
<script type="text/javascript">
function followLink(o) {
var a = o.getElementsByTagName('a');
if (a.length > 0) {
document.location = a[0].href;
}
}
</script>
</head>
<body>
<table>
<tbody>
<tr>
<td style="width: 100px; height: 30px;" onclick="followLink(this);">
<a href="http://someplace.com/file.php">apa</a>
</td>
Additionally, you might want to skip the td:hover style since this will give non-script users the impression they can click something which is not clickable for them. Instead, add onmouseover/onmouseout events for the table cells and change the cursor through javascript.
