The way I see it is that table T528t along with the other repository objects are grouped into an HR Master data package that is available from the SAP_HRRXX s/w component (that is only available in HR activated systems). The Org.Mgmt tables are available in SAP_BASIS s/w component that is enabled in all SAP ABAP systems, as part of BC-BMT-OM appl. hierarchy . Hope this helps!
Pawan.