Everyone knows about the last minute jitters before speaking in public. Depending on your style, you may find it helpful to isolate yourself so you can focus on the task at hand and calm your breathing beforehand. For others, mingling and talking with others helps them remain relaxed.
I've worked with pairs of fundraisers where one was happy to talk to the crowd before the beginning the formal part of the evening and the other would wait in an adjacent room.
For myself, I find that when I'm giving a big presentation, I like to be on my own to gather my thoughts and focus but when I am running a panel, it's much more helpful to me to talk to people and even use the chance to hone my questions more tightly.
Chances are, you know what would suit you best.