I wrote up some recommendations about implementing paginated collections.

https://ghost.evanp.me/implementing-pagination-for-activitypub-collections/

tl;dr (read the full article for the whys):

• Have big pages – 128 or 256 items per page.
• Inline the items for small collections.
• If you're already using offset pagination, change to cursor pagination ASAP.
• If you're implementing from scratch, consider using bucket pagination.