What do you mean by "Trash" Can you give us a screenshot of part of the contents showing the actual files in there. Not sure waht you mean when you say "can I reduce the amount to what I put there like in XP?". If you don't delete anything then nothing will go in there. If you wish to delete files completely without going into the recycle bin then hold down shift key whilst pressing the delete key!
EDIT:
That was odd, none of the above posts were showwing when I posted. he timings were a bit tight perhaps