There are numerous reasons that can make a seat or table change a good move. If you have a very aggressive player to your left who is raising every hand and you never get to see a flop it may be time for a switch. If someone is abusive or too drunk you may want to get up too. If you crave action and you are playing with a very tight crew move to a more aggressive table. It is your right to move and you should do if you feel the need. A word of caution. In some instance in a Casino card room if the tables are too short they may not let you move as they want to keep the players per table at an equal level. Casinos and players don’t want 5 people at one table and 9 at another but it certainly cannot hurt to ask.