I am pretty much a newbie so I apologize if this post is "sub-par"

My site has a header image which is header2.png

The header image currently lies on all pages of my site...

What I want to do is keep the current header on the homepage and then have 8 additional header images per category. Below is a snip of a portion of the code of the main html class that every page of my entire site uses:

<table class="header" border="0" cellspacing="1" cellpadding="0" width="100%" height="130" style="background-color: #FFFFFF;">
<tr>

<td width="858" colspan="10"
style="background: url(<?=$this->image_url?>/header2.png) no-repeat top left;
padding-right: 35px; font-weight: bold; font-size: .75em;"
valign="middle" align="right">

Can you please tell me how I can specify a header image that relates to each different category. Thanks