In my view, the tabletop games community is generally a friendly, welcoming group of people. We seem to know that we are all human beings, and each of us has different skills, experiences, backgrounds, challenges and attitudes. We do our best to ignore stereotypes and prejudices and try to allow anyone join in the fun of escaping to another world, solving difficult puzzles or do whatever constitutes playing a game. Of course, our community isn't perfect, but I would say the trend is in the right direction. The same is true for modern games, and many designers and publishers are clearly doing what they can to allow more people to join in the fun. There is still more work to be done of course, but again the trend seems to be in the right direction.
If you play tabletop games with friends or maybe even in a games group, you may have come across certain taboos. There are things that people don't like you doing. Some of these are to with ensuring that there is no cheating, others are about keeping a game in pristine condition, others are just some sort of personal house rules or traditions. Different people or groups will have different rules, and many will seem obvious or sensible, but others may feel unusual.