Then use the class on the table cell you want to apply your background image to:
Code:
<TABLE>
<TR>
<TD CLASS="tdbackground">
Your content here
</TD>
</TR>
</TABLE>
In Dreamweaver, once you create the class in your stylesheet, (in design mode) select the table cell, then go down to the properties section at the bottom to apply the style class to it.
Thanks for your quick response. To take it one step further, how would you go about preventing tiling when adding a background image to an entire page (no table)?