I hope you don't mean editing the CD-ROM discs as they are, because they're, you know, read only. Unless you installed a mod in your PS2, you're not going to be able to play burnt CD-Rs.
Maybe I'm misunderstanding you, but the thread title and your post suggest you're saying "can I edit CD-ROM discs and put them back into my PS2", in which case the answer is hell no. If you work with an image file then sure, you can change stuff, but to play it on the PS2 you'll need some kind of mod.