Print table footer at the very bottom on last page
If you're only supporting Firefox, this is actually really easy. (Skip to the edit to see a technique that also works in IE but is less versatile. Chrome and the other webkit browsers didn't support repeating footers when I posted this answer, so I didn't test them).
All you have to do is add a large bottom margin at the end of your content. The exact size doesn't matter, but it must be large enough to be guaranteed to run past the end of the page. I recommend making it at least as large as the maximum paper size you think your users will use.
Don't worry, this won't add a blank page to the end of your document. Margins differ from other forms of white space (such as padding and <br> tags) in that they get cancelled out when they exceed the page boundary (see spec, section 13.3.3). Both Firefox and IE will delete the margin, but Firefox will still generate a footer at the bottom of the page as if a page break had occurred. (IE, on the other hand, behaves as if the margin was never there, which is why this approach doesn't work in that browser.)
You can put the margin on a pseudo-element to keep your HTML tidy, and you can use @media print to prevent it from showing on screen.
Here's the code. To see it work in Firefox, open this jsfiddle, right-click the output, select This Frame > Show Only This Frame, and do a print preview.
@media print {
#content:after {
display: block;
content: "";
margin-bottom: 594mm; /* must be larger than largest paper size you support */
}
}<table>
<thead>
<tr>
<th>PAGE HEADER</th>
</tr>
</thead>
<tfoot>
<tr>
<td>PAGE FOOTER</td>
</tr>
</tfoot>
<tbody>
<tr>
<td id="content">
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content
</td>
</tr>
</tbody>
</table>EDIT
There's another option that works in both Firefox and IE. All you have to do is put the footer in a separate <div> and fix it to the bottom of the page, and then use the repeating <tfoot> as a spacer. This approach does have some minor drawbacks, though (details below snippet).
Here's the code. To see it work in Firefox, open this jsfiddle, right-click the output, select This Frame > Show Only This Frame, and do a print preview. In IE, click in the output frame, hit CTRL+A, do a print preview, and change "As Laid Out On Screen" to "As Selected On Screen".
@media print {
#spacer {height: 2em;} /* height of footer + a little extra */
#footer {
position: fixed;
bottom: 0;
}
}<table>
<thead>
<tr>
<th>PAGE HEADER</th>
</tr>
<thead>
<tfoot>
<tr>
<td id="spacer"></td>
</tr>
</tfoot>
<tbody>
<tr>
<td>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content<br>
content<br>content<br>content<br>content<br>content<br>content<br>content
</td>
</tr>
</tbody>
</table>
<div id="footer">
PAGE FOOTER
</div>The main limitation of this method is that it puts an identical footer on every page in the print job, which means you can't have any pages with a different footer, or no footer. Also, since the height of the spacer depends on the height of the footer, you'll have to adjust it if the footer height ever changes.