1. Open the Contacts/Address Book application and select the contacts that you want to export. You can select multiple contacts by holding down the Command key and clicking on the contact entries. To Select All, click on the first contact, scroll to the bottom of the window, hold down Shift key and click on the last contact.
2. From the Menu bar, go to File > Export > Export vCard. In the pop-up dialog, select the save location (Desktop), and then click the Save button.
3. Unfortunately you cannot export to a CSV or XLS from Mac Contacts/Address Book, but you can search the App Store for many conversion apps (Export Address Book, for example). Alternatively, you can send the vCard (or .vcf) file to firstname.lastname@example.org and we can convert it to a CSV for you.