Hi,
I've just checked the PostgreSQL code and I see that there are views generated on top of the _... tables. I think it has to do with the fact that you cannot write instead of triggers on tables in PG.
So it creates the _... tables and also views with the 'original' name on top of the _... tables. The views have the triggers needed to let everything work correctly.
I hope this clarifies it a bit.
Regards,
JJ.