Books Categories not syncing with iPad

Hi,

I'm using OSX 10.13.6 and iOS12

On my apple, I have 18GB of books (mostly PDFs) in in about 100 categories. This is for my work. Of late (since iBooks became Books), when I sync my iPad to Books (via iTunes), although newly PDFs are copied over to my iPad, new Category names are not.

I have searched online for an answer, and it seems that i need to switch in iCloud for Books to resolve this issue?

I do not want to do this because Apple only offer 5GB of Cloud space free of charge, and my document archive is 18GB in size - so iCloud is switched off on all my devices (in fact I do not use iCloud at all as it causes problems with trying to maintain separate Notes on iPhone and iPad!).

So my question is - how can I get new categories created on Books to be synced to my iPad, without the use of iCloud? Surely there must be a solution that does not compel me to pay Apple a monthly subscription for iCloud space I otherwise do not need?

Thanks,

Kevin Nolan,

Dublin