I hope you didn't get your expectations high when you saw a reply to your post, but you might like to take a look at this:
http://www.smooth1.demon.co.uk/ifaq08.htm#8.34
They have a shell script to list out all tables in a given table space. Once you can get that working as a shell script on your system (and I hope you are not on a Windows platform), then you could use the EXEC() function in PHP to grab the result of that script.
HOpe this helps somewhat..
Shanx