I'm not sure how much memory the books I've downloaded are taking up, or even if it matters. I'd like to move them to an SD card or flash drive, but I can't even find the book files... and I have no idea how to move them off my tablet. Also, speaking of books, what's the difference between the files being "on device" vs "archive". Where do they go if they are archived? Does that save space? Thanks in advance for any help you can give.