It might work as long as the file system semantics are the same. The PI is case sensitive. Is the Mac? You could try it then run library check to see if you have any problems.
In any event, if you go this route you must copy both the calibre library and the calibre configuration directory. You can find your configuration directory on using Preferences / Advanced / Miscellaneous / Open calibre configuration folder.
If I were to try this (which I probably wouldn't) I would:
- Create an empty library on the PI.
- Find the PI's configuration folder.
- Copy the library from the Mac's library folder to the PI's library folder.
- Copy the configuration folder from the Mac to the Pi.
- Hope everything works.