So... your problem is a LOB column using too much space?

Statement below will move table to new tablespace BUT will not move LOB segments from current tablespace...

ALTER TABLE table_name MOVE TABLESPACE target_tablespace
/


Statement below will move segments that make up specific LOB column to new tablespace...

ALTER TABLE table_name
MOVE LOB(clob_column) STORE AS (
TABLESPACE target_tablespace
)
/

If your problem is just the LOB column I'll do just the second one.

Hope this helps.