So really it's about deciding what sort of occasion it is, and what sort of impact you want to make.
- Is it really a ladies-who-lunch afternoon tea, with a few rounds of questions as the excuse for getting together? Try a charming but understated day-dress, or your favourite too-cool-to-care designer jeans and top.
- Are you a nerdy-geek-who's-going-to win? Nothing wrong with the same comfy jeans and a tee-shirt / jumper that you wear everywhere - and besides you won't be reading this post anyhow, because you're too busy studying for the quiz.
(But if you do have a set of Google Glasses, or a jacket with Encyclopeadia Brittanica encoded into the sleeves - and you're ok with using tools like that to help you win - then go right ahead and wear them.)
- Or is it a swish charity fundraiser, with everyone-whos-anyone going to be there. Definitely a LBD for ladies, and a tux for the gentlemen
- Have the organisers said that it's fancy dress? Get your imagination working overtime.
More likely, though, it's none of these. Just an ordinary night out with a group of friends and maybe some friends-you-haven't-met-yet. So wear whatever you would usually wear if you were going to a movie, bowling, concert, play, etc with these people.
Whatever way you go, the bottom line is this:
What you really need to wear to a table-quiz are clothes: very few quizzes are held in nudist camps.