After a while the browser starts to lag

[ARRA]

Chromium only keeps History for 3 months by default.
Older History will be deleted automatically.
Maybe the file size is not real reason, it is possible that this file gets partially corrupted.
I think there is a bug in Chromium that can easily corrupts History database.
And what anti-virus are you using?

I don't use antivirus, the built-in antivirus from Windows is also disabled. I can no longer see the date of the last entry in history, but I doubt that I downloaded 5000 files in 3 months. Was there any way I could turn off automatic cleaning?