Just one, or a few, contacts?
Try sending it to your iPhone via email or SMS (Text Message).
In Mail on the iPad, tap an hold on it for an option to add it to your Contacts app.
In Messages, tap the blue arrow to the right of the card. There should be a button to add it to Contacts.
For all of them, you could try visiting your phone service provider and asking them to transfer the contacts. Most usually offer this service when you get a new phone, so they may be willing to do it ad-hoc. All they can do is say no.
I'm sure there are other methods, but that is all that comes to mind at the moment.