Thank you everybody for your quick help, you guys R awsome.

This may be an added experience to some readers here.
I exported tables from user1 to export1.dmp. Those tables were originally placed in tablespace TB1
Then I logged in as user2 who has dba role and default tablespace TB2
I imported export1.dmp fromuser=user1 touser=user2
I got the tables places in TB1 owned by user2 !! they were supposed to go to the default table space TB2
(This when I needed to move the tables from TB1 to TB2)
I revoked the DBA role from user2 and reimported export1.dmp using User2, then the tables went to the default tablespace TB2

Regards