leveldb minimize compilation dependicies design

I know leveldb use Interface class to minimize compilation dependencies between include/leveldb/db.h db/db_impl.cc, include/leveldb/comparator.h and util/comparator.cc
But why include/leveldb/table.h, include/leveldb/table_builder.h use Handle class struct Rep, Rep rep_ to minimize compilation dependencies.

what's the consideration behind these two design?