This is not normal, of course. There are users with several 1000 items in the Repo not having issues like this. Do you test this page as admin or standard user? If you are testing as admin, the cache will be ignored with your settings, which could lead to a longer loading time, but not as long as you describe.
Without the opportunity to take a closer look, it is difficult to find an explanation. You are welcome to create a ticket and send me access data so I can take a look at it.