I took what I wanted to my Ohio interview, and didn't worry one iota what anybody thought of it, but that's me.
I had all the things that I wanted to review prior to interview: notes I had taken about current events/etc, my VMCAS, my supplemental, a notepad for jotting things down at the lectures following my interview. And I shoved it all into a simple manilla folder cuz that's what I could dig up at my house before I left. I also had no pockets (damned women's clothing!), so I was carrying my wallet, a tin of Altoids, and my car keys (which I managed to misplace, and had to go back and interrupt my interviewers' deliberations post-interview to see if I'd dropped them in the room somewhere).
Certainly didn't hurt my chances!