Is that possible to upload some videos from my macbook (itunes library) to apple tv? This way, I can watch that movies without use my macbook or any kind of streaming.
Depends on which AppleTV you have.
With the 1st generation you can select which videos from your media library to sync with and iTunes would copy them to the AppleTV.
Unfortunately the 2nd generation doesn't have any internal storage, so it can only stream videos.