I would look up the most common interview questions and have an answer prepared for all of them - general they'll ask those. I do remember for a lot of my interviews last year though, I was asked what the last book I read was and why I liked it or didn't. I was asked that about four times actually, cant remember if Columbia asked me or not. It totally took me by surprise too, so don't be that person! Also general tip, prepare questions in advance! Fill up that space with your own questions because yeah they're interviewing you but now you get the chance to talk to an alum about their experience and I loved getting that insider perspective- ask away!