Q: How do I print return labels with the Apple Contacts application?

There are some basic Label outputs if you select some (or only one) contact and call the dialog for printing. You can configure (just a little) the output of your labels. If you want more, you can save first the output as pdf and then work on it.

I'm trying to print a page of the same contact (return labels).  I understand how to print different contacts but not a page of the same one.

I will try to give you a workaround:

1) select the one card you want to print many times

2) call the print dialog and let configure this: Styling > Page > DYMO - Shipping Labels (you must see your contact size filling on the Demo-Page-Format)

3) don't print, let only open as PDF in preview an let you show the thumbnails (cmd+alt+2)

4) do this another time, so that you have two open PDF with you label with thumbnail (on the left)

5) drag so many times (5, 8 or 15) one thumbnail on the other open pdf so that you have the right number of "pages" that you want to print on your A4 (or US Letter).

6) now you have i.e. a PDF with 9 identically pages and you can print from PDF choosing in layout "print 9 pages per Sheet)

7) Enjoy cutting your labels

I don't know of a way to do it from Contacts. I use Avery Design and Print software which is free and works well: http://www.avery.com/avery/en_us/Templates-%26-Software/Software/Avery-Design--P rint.htm