this is not really a php problem. go to your site, and look at the html source code. it reads:
<img src=PC Shop/images/printer cable.gif width="213" height="158">
I wouldn't use spaces in directory or file names at all, and you should put it in quotes.
echo "<td width=\"26%\" rowspan=\"2\"><div align=\"center\"><img src=\"".$myrow["smallimage"]."\" width=\"213\" height=\"158\"></div></td>";