I perform for my family members mostly, so sitting at the table kind of gives me more intimacy (not in a weird way lol) and lets me know they pay more attention. I can definitely handle many card tricks standing up, especially if surrounded by spectators. But for some reason, sitting at the table gives me more cosiness. Also, some tricks and techniques, especially with coins are better if performed seated. I usually work with one spectator at a time, so that's also an advantage. Also, I want them to follow the trick, not just let me finish performing and then, once they realize it had a good ending, ask me to do it again. I continuously ask them to keep following the trick. Sitting at the table makes it easier, but I can definitely handle standing up