1. The light at one end of the table is poor
2. The wall is white and you cannot see the ball very well
3. The umpire appears to have got an edge ball decision wrong against you
4. Your opponent is wasting time or stopping play by saying your serve is illegal
5. The crowd are clapping against you
In the case of a poor decision I would suggest leaving all decisions to the umpire as they are doing their job and you should do yours. Good and Bad decisions even themselves out over the course of a match. I would also recommend ignoring everything as much as you can. Focus on the game and your tactics. The table end with the bad light will also be used by your opponent. If you complain you LOSE. I got more enjoyment from winning when my opponent did all the moaning and I kept quiet and focused.