You can only delete personal address books created from Frequent Contacts. You cannot delete the Frequent Contacts address book. Also, when you delete a personal address book, the contacts in that folder are removed with it. Deleting a personal address book folder does not remove any of the contacts in the folder from the GroupWise Address Book.
To delete a personal address book:
Right-click the personal address book under Frequent Contacts and select Delete.
Click Delete in the confirmation prompt.