Edit: just checked rame usage in task manager, Bitcoin Core using only 500 MB. while Google Chrome using a whooping 2 GB ram. lol
Chrome is an awful browser for many reasons, and resource usage is one of them.
In Bitcoin Core, go to Settings -> Options and check the size of the database cache you have set. Increase this if you want Core to use more RAM (you'll need to restart Core after you change this setting).