The link given by Pondus, won't actually do what you are asking "is it possible to bulk import a list of websites for blocked websites".
Avast doesn't have that feature and it would have to be maintained as an out of date list isn't worth much.
The Avast Web Shield is the primary defence against malicious websites, etc. and that is constantly maintained by Avast.
What Pondus is suggesting is (I believe), if there is a website that you feel is malicious and isn't detected by Avast then you can report it to Avast for investigation and inclusion if required.
No Idea why you are using such a large text ?
If visually impaired fine, otherwise it is considered shouting.
