[rtiangha]

Originally Posted by MashaT

You are right. I am calling it series because that's what Calibre calls it. On Kobo they show up under Collection tab. Series tab is whatever Kobo makes of them on its own. My biggest collections include several that are between 80 and 140 books.

I agree with DNSB. There's no need to create Collections based on Series name anymore because newer Kobo firmwares now automatically organizes them to its own tab (it was useful on older firmware because there was no easy way to view by series without using the search box). So deleting those redundant Collections and preventing Calibre from automatically creating new ones each time you upload a new book series may help with your speed issues.

When i connect Kobo to PC, it looks like Calibre created folders based on authors name and it becomes a whole lot of folders because apparently depending on book's source some authors are listed First, Last name as one folder and Last, First name as another folder.

This part is fine.

Will it help divide my collections of 50 books+ into smaller ones?

I don't think so; deleting those redundant Collections will probably do it; things probably slow down past a certain total number of Collections.

Honestly, this feels like a bug or optimization problem to me. I would understand things getting slow whenever you access the Collections tab, but for everything to be slow whenever you tap on something if you have a large number of Collections or a Collection with a ridiculously large number of items has always seemed weird to me.

Just curious: How many Collections do you have on your device?