the “url blocking” seems to act the same as an ad-blocking host file
http://www.mvps.org/winhelp2002/hosts.htm
would be good if such a hosts list could be added to “url blocking” in one go, stripping
127.0.0.1 and #comments.
URL blocking in WebShield is quite different. First, it’s for HTTP (web sites) only. Next, it looks quite different when you try to access a blocked site - try it yourself.
About the possibilty to import the list - here was some discussion about this http://forum.avast.com/index.php?topic=10803.0
The answer is “sorry, not at this moment”, a much more complete URL management package may be actually part of one of our upcoming products… 
Cheers
Vlk
thanks vlk, I didnt see the previous discussion.