I believe that's correct, DerekA-- which is another good reason to organize the files on different USB flash drives, one category per flash drive, preferably smaller size drives (to avoid paying more for space you can't use), possibly color-coded for different categories.
Or, if you prefer to keep everything on a single flash drive, have the style files sorted into different folders and copy just the ones you want to use into the root directory as Vinciane suggested.
I'm not sure about the limit being 100 files, though-- that's the limit on User files, because they have a number in their name and the number must be 001 to 100. I think the limit might be something like 250 for style files-- unless that's for song files.