In table tennis, who are your friends and practice partners that you hang out with?  Are they negative, controversial troublemakers?  The Bible says that you will be like your companions. 
Proverbs 13:20  He who walks with wise men will be wise, but the companion of fools with suffer harm.
 
If you want to have a more positive, uplifting tournament experience, consider hanging out with wise men.  If you are around fools, consider being the positive influence on the group.  Whether it be in warmup, during a match, or after a match, choosing your words well is the key.  In addition to talking about friends, the book of Proverbs in the Bible also talks about choosing the right words…
Proverbs 25:11  As apples of gold in settings of silver, so is a word spoken in the right circumstance.