I don't know where you get the too greedy bit from, your image certainly doesn't show it.
Certainly not for HDD use and the RAM use is even lower. Yes your HDD use is showing 100% (but not assigned to avast), nor does the CPU or Memory, but RAM at 132.4MB (just compare with your browser) is higher than I normally see on my system.
It is easier for those helping on the forums if you post, attach images in the topic, as I have here.
What s it that you are doing when you consider Avast to be hogging your HDD space ?
What other security based software do you have installed ?