I think, the best advice to “fill in the silence” nerves is… be yourself.
If you don’t feel comfortable in the silence say something. If you don’t feel comfortable speaking with people you’re around, stay quiet.
You are the only person you have to spend the rest of your life with, and that’s the person you want to please most.
And this is easier said than done, and it is ux specific, after all, we are all users of life
Ok, I’m not nuts but seriously, being yourself, not wondering at each step how to behave, what to say is not an easy thing but the truth is, there will be people who will like you and people who will not. So, (look above), be the person you want to be and just let things flow.