I am running Android 4 on SAMSUNG Galaxy Note 10,1, and using the S Note app, Is there a way to process multiple SNB files at once? For example, S Note can export 1 SNB to PDF but not multiple, but it would be better if there's also a way to export multiple SNBs to a single PDF
Yes, it is possible.
Try to go at the root of the note program. From a note, click the back button, then click on 'most recent notes' to see all notes. If you select "share", you'll be given to select more notes, or even folders.
For more information on compatibility, please provide with your exact version of s-note.