Open the email in question, then click on the name of the sender in the header. You will see a dialogue box and one of the choices will be to "Add to address book". Click on that link.
I guess I didn't make myself clear. A friend emailed a mailing list from his outlook. I want to copy them from that email and move/paste them into my Comcast address book.
Then how did he send it? If it's a .csv file or a vCard file you should be able to import it. But that assumes he exported his entire address book and sent it to you. There is no way I know of to break out a group list from an address book and export it or import it. It's all or nothing.
So if he sent you a .csv or vCard file, then open the address book, and in the left pane on the landing page click on "Address book" again, and you will see a "hamburger" icon to the right. Click on that and you will see the option to Import.