You can transfer your films either by doing the following.
Linking ur ps3 upto ur pc and via a ps3 media server copy them from the selected folders.
Burn them to a dvd and copy them over, copy the films onto ur Usb stick and copy them on the ps3.
Or get yourself a Usb external harddrive copy the films onto that and plug it in, The ps3 will read it
As most films are about 700m you will beable to fit a fair number onto the ps3.
If the films are HD films then that will eat up more memory as the files are alot bigger. So would be best either to burn them onto dual layer dvd, usb harddrive or stream them across.