Hi everyone! After spending many hours triyng to find any solution for the RAM memory leak increising while playing, apparently I've found a solution that it's working for me and the game is going fine now (no RAM issues, note: I've no tried in big sieges at the moment).
Well, I have 2 SSD and 1 HDD. I had Bannerlord and Steam installed in one SSD to SATA II port in my computer. I only have one SATA III port and it's connected to the other SSD which it has OS and is booting the system through SATA III port. I've changed the SSD with Bannerlord installed to the SATA III port and the SSD with the system to another SATA II port (changing the disk booting options if needed). And magic, now the game works perfectly and smoothly after 2 or 3 hours playing.
I don't know if it could be your problem as well, but check what kind of port is connected to the disk you are running Bannerlord.
(sorry for my bad english)
Cheers!
PD: I'm with 1.0.10 version