Should I take extra books to a signing for friends who aren't attending?

By the night before the signing, there were six books in my tote. Only one was mine. I'd said yes when a friend asked for a birthday dedication, then four more requests arrived.

The event email asks attendees to bring no more than two items. One friend says that probably means two per person whose name goes inside, and another suggests I queue twice. I haven't asked the organiser.

I want the author's time for my own question too. Instead I'm checking spellings, carrying other people's books and worrying about being the person who delays the line. I helped create the expectation by accepting before reading the email.

How do I reduce this to something I can actually ask for at the event without making the friends who handed over their books feel I've casually abandoned a promise?