I am currently at 20.7.2425 (build 20.7.5568.598).
I see no memory leaks on avast premium security. Well, I am spending more than 50% of RAM when browsing, but mainly due to the browser.
Screenshoot: https://prnt.sc/un29i8
System: Windows 10 Home (Build 19041), i5 2,5GHz, RAM 12GB.
It is preferable to attach images to post rather than give off-site links (who knows what is there) 'Attachments and other options' option below the reply window.
That said, on your off-site image, collectively all of those avast processes don't add up to much (certainly not on 16GB of RAM). I don't see anything for the Avast Secure Browser if that is the browser you are using ?
I don't use it now, so I can't recall what service is used.
The latest build is 20.7.5568.599, I don't know if that might help, but a system restart should bring it up to date.
But for me Avast Free is relatively light.
Browsers do tend to be heavy on RAM (multiple tabs plus the main service) my default browser Firefox is currently using 1,440.6MB and that is a lot on a 8GB RAM system.