Mass Contact Deletion
Is there a way to delete multiple contacts at the same time without having to download a separate 'contacts' app??
Not if you are wanting to be selective of what you delete. If you are using iCloud, you can turn off iCloud Contacts, which will prompt you if you wish to keep them, select no, and they are gone. If you just wish to get rid of some of the contacts, you can do it on a computer.