irgendwie bin ich mir nciht sicher, ob tbody höhenangaben beachtet...
nur ein schneller versuch, firefox 2 stellt das etwa so da wie ich mir gedacht habe:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Titel</title>
<style type="text/css">
body { background: yellow; }
table {
width: 500px;
}
td, th {
border: 1px solid black;
padding: 0px;
margin: 0px;
}
thead {
overflow: auto;
}
tbody {
background: red;
height: 7em;
overflow: auto;
}
</style>
</head>
<table>
<thead>
<tr>
<th>1</th>
<th>2</th>
<th>3</th>
</thead>
<tbody>
<tr>
<td>foo</td>
<td>bar</td>
<td>baz</td>
</tr>
<tr>
<td>foo</td>
<td>bar</td>
<td>baz</td>
</tr>
<tr>
<td>foo</td>
<td>bar</td>
<td>baz</td>
</tr>
<tr>
<td>foo</td>
<td>bar</td>
<td>baz</td>
</tr>
<tr>
<td>foo</td>
<td>bar</td>
<td>baz</td>
</tr>
<tr>
<td>foo</td>
<td>bar</td>
<td>baz</td>
</tr>
<tr>
<td>foo</td>
<td>bar</td>
<td>baz</td>
</tr>
<tr>
<td>foo</td>
<td>bar</td>
<td>baz</td>
</tr>
<tr>
<td>foo</td>
<td>bar</td>
<td>baz</td>
</tr>
</tbody>
</table>
</body>
</html>