DBA_TAB_PRIVS

All grants on objects in the database

Columns
   ___________________________
 
   GRANTEE
      User to whom access was granted
   OWNER
      Owner of the object
   TABLE_NAME
      Name of the object
   GRANTOR
      Name of the user who performed the grant
   PRIVILEGE
      Table Privilege
   GRANTABLE
      Privilege is grantable
   HIERARCHY
      Privilege is with hierarchy option