Various objects are available to query the underlying meta data.
select * from qsys2.sysviews where view_owner ='xyz' and TABLE_NAME = 'tab1'
select * from qsys2.systables where table_owner ='xyz' and TABLE_NAME NOT LIKE 'SYS%'
-- Stored Procedures, SIMILAR RESULTS from sysroutines
select * from qsys2.sysprocs where routine_schema ='xyz' and ROUTINE_NAME NOT LIKE 'SYS%'
Other catalog views
SYSINDEXES
SYSKEYS
SYSPROCS
...