I was at an on-camera audition this weekend. For a company that schedules their auditions so that every actor called for a particular role comes in at the same time. (all the 'dads' at 4:00, all the 'nurses' at 4:30, etc.) When you show up, you fill out an info sheet, get assigned a number, and get seen in the order you arrived.
As you can guess, this means some wait around in the hall time. What do you do when you've got wait in the hall time? Review the audition material is usually good, but at this company, which produces a re-enactment show for a foreign market, the audition is an improvised situation, taken from the news story that they're re-enacting that week.
So, back to square one - what do you do? I usually bring something to read. I've auditioned for this company in the past, and have waited 30 minutes or more to be seen by the casting folks. Reading keeps me occupied, it's quiet and doesn't disturb anyone else, I don't miss any announcements (why I don't listen to music), and I stop when they're about 2 people ahead of me to get focused on the audition. If someone talks to me, I might talk to them, but I try not to get too involved in conversations, both for my own sake, and out of respect for other auditioners.
This weekend, I watched a woman come in to the audition, and immediately begin pestering the woman she sat next to. First she needed a pen, then she wanted to know who did the other woman's headshots, how she'd found out about the audition, if she knew of other casting resources besides SF Casting, if she'd ever lived in LA (the first woman had lived there 3 years), she told the other woman about the production company she was planning to start in 2011, and basically didn't stop talking the whole time she was in the hall. And while she was annoying, my heart went out to the other woman, who clearly didn't want to be in the conversation, but didn't know how to extricate herself from it.
Here's the deal. Your prep time is your prep time. If you don't want to answer someone else's questions, let them know you're prepping, okay? It's perfectly fine. I do this and see it done all the time. You see someone you know at an audition, say a quick hi, and after you've both finished up, you go grab a coffee, or you talk outside. If one area is too chatty for you and you need quiet, or if you need space to stretch or warm up your voice, take it, (where you won't be in anyone's way or disturb the audition room), and let the person running check-in know where you've gone.
So much of the audition process isn't in your control. But this is. So take charge of what you want to do with prep time.