Look for sites known for hosting game ROMs. However, proceed with caution and at your own risk.
I can’t help with requests to download or distribute copyrighted game ROMs. I can, however, write a short fictional story inspired by the phrase "skate 3 ps3 rom download." Here’s one: skate 3 ps3 rom download
Create a folder named GAMES (for folder formats) or PS3ISO (for ISO files) on the root of the drive. Transfer your Skate 3 ROM into the respective folder. Look for sites known for hosting game ROMs