This has happened to me several times, but I never considered it a problem because My Laptop is slow. But when I had high CPU and RAM consumptions, I took to disabling Hardware Acceleration, and upgrading whenever available. I stopped using Brave Browser and switched to Brave Nightly. I currently have no performance problems when I have more than 6 pages open.
Possible solutions
1- Clean your Laptop, and its components, do some maintenance.
2- Disable/close programs that you do not use.
3- It may not be a Keylogger coming from Brave, it may be a Virus that infected Your Laptop, when you downloaded something.
4- Try other Versions of Brave.
5- Defragment the Disk
6- Use the Maximum Performance function on your Laptop.
7- Use these Flags that I use in My Laptop:
I hope it was of some use to you, although I doubt it very much hehe