Certainly. In Safari or in the DEVONthink browser you can select all or a portion of a displayed Web page as a rich text note - keyboard shortcut is Command-) - or as a WebArchive - keyboard shortcut is Command-%.
Where will the new content be saved? That depend on your choice in Preferences > Import - Destination. You can choose to have new content brought in by Services or scripts saved to the Global Inbox, or to the Inbox of the frontmost open database, or you can choose ‘Select group’ and directly save it to any group in any open database.