Thanks for providing the links for read. Now I more or less understand how this got started.
When I read in the web that avast is efficient and takes up only 7+MB of memory, plus many of its positive attributes, I became interested. But Windows taskbar of my PC shows that avast actually takes up much more than 7+MB, 17MB to 19MB in fact. I became concerned. After joining this forum, I finally realized that it is normal and nothing to worry about.

All in all, it is the misinformation of 7+MB memory footprint that started this discussion.

Just a moment I installed avast onto another PC (P4 3.0E with 512MB RAM). And truly ashServ takes up 18MB of VM. I reckon this is normal and nothing to worry about.