EXPDP creating tables

  EXPDP creates SYS_EXPORT_SCHEMA tables every time in runs.

Is it necessary to save these tables to restore the file with impdp?

Can these tables be dropped after some period?

My schema Size growing because of these tables rows growing ..

As I run expdp of schema everyday as backup script, must some logic to cleanup.

When I created training schema instance for another DB using same expdp size is extensively less.

The outsource company project suggested to use expdp as there at 20 LOB Object and user defines object types which were not handled by classic exp utility.

thanks in advance ..