What position, junior designer? Mid-level? Creative? Is this in a studio, or for a business that have an in-house team?
Ultimately I suspect they'll be asking about your approach to work, how you came up with X idea in your portfolio, techniques used, how up to date you are with technology/software/techniques, as well as wanting to know a little about you as a person. Be honest, and don't be afraid to admit you don't know something if you don't. Studios typically have someone or several someones that fulfil specific roles, such as artworking for example. If you're not an artworker (or whatever), don't claim to be, it will just bite you in the arse when you mess up a huge print order.
People hire people, so don't be afraid to just be yourself. Even if you're not exactly what they're looking for, if you come across as a nice person who can fit into their team straight away, you might get in. Good luck!
I have a couple of friends who left uni and went into positions in an in-house team, and they quickly found it was not what they were hoping for. It was very much business-orientated (they have to dress in office attire), and they were actually the only ones on the team, so they weren't getting any help from experienced designers.
I'm not saying this is the case here, just be sure to only take the job if it sounds right for you. The interview is as much for you as it is for them.
you will most probably get bored of using the same pantone, coupled with the same logo. It can be a great place to gain some experience and learn technique and how to set things up etc. Have worked for 3 big brands in house so am speaking from experience
Take everything that could be relevant with you (within reason!) so that if appropriate you can refer to. When interviewing I always think CMF - capable? motivated? fit in? Be genuine, be yourself and show passion / desire / drive.
Yep, as mentioned, take anything you might need, just in case. Just be sure to keep it hidden away in a neat folder or something (might be worth hiding it under a pad of lined paper - taking notes always looks good, and shows you're interested and organised).