Could you explain a bit, what exactly is stored in these csv files?
Are the image paths or is the raw data somehow stored there?
Anyway, I think the easiest approach would be to write a custom Dataset, and load the data lazily in the __getitem__ method.
PS: I’m not a huge fan of tagging certain people, as this might demotivate other users to post an answer in your thread, who might have a way better answer than me.