How to find which tables are populated with data

Hello I need a little help as I'm very new to the DBA game!!!! Is there a sql statement by which I can select tables on a particular database to see if they are populated with data ? I've tried select * from systabnames where dbsname = 'testdb' This has returned the system tables as well as tables on my 'testdbs' but does not state whether they are populated with data. Also, I've been dropping stored procedures individually, with similar prefix ie address_a, address_b, address_c, agent_a, agent_u, agent_s1 etc. Is there a way that I can select these and then drop them all at the same time? TIA David