There doesn’t seem to be a way of assigning several contacts to a single tag in a single step in the Address Book. I lost all of my categories (what Famundo seems to call Tags) when I imported my contacts. For example I have a tag “Healthcare” that I assign to all my Doctors and healthcare providers – so that I can find them quickly. I had to go through and edit each at every Healthcare contact one at a time and assign them a tag—I am doing a few each day of the other contacts but its a pain. Please consider adding a convenient one step way of doing this.