Froissart’s Chronicles, the lay of roland or any other chanson de geste, piers plowman, the canterbury tales, de rea metallica, on divers arts, gawain and the green knight, …
possibly too early, late, or religious: beowulf, the anglo-saxon chronicle, the chronicles of matthew paris, shakespeare…
Brilliant. This is going to take some time to go through, but after 20 minutes of Googling and reading bits and pieces it looks like pretty much exactly what I was thinking about.
> are there any interesting medieval books that are not bibles/religious texts
Yes. All of them.
The thing is that manuscripts were expensive. And fancy manuscripts with colors and drawings and gold leaf were even more expensive. That meant the required well-monied patrons. And often that meant the church. Or some noble intent on going to heaven who really needed a spendy book of hours to help get there.
There were others, though. Check this out: an early sort of graphic novel about Alexander the Great!