Hi Subbu,
Kindly ask your DB team to perform high water mark activity on associated tablespace( <SID>#POOLD and <SID>#POOLI)
For better understanding refer below link
DB2 9.7 New Features – Reducing the High Water Mark
While for specific table as a part of housekeeping you can clean up the BW authorization log table RSECLOG using transaction RSECADMIN as described in SAP Note 1592528.
Br Vaibhav