Health
Table Tennis is a sport for life,
It is seen as good for Mental Health. It is a social sport, it is an uplifting sport. Exercise is generally recommended for mental well being. TT gives you this exercise. Moving around playing TT shots, winning points and having fun does not feel mentally like the 'exercise chore' other exercise activities can be. It is something to look forward to beforehand. It is fun and feels positive before, during and after. You can switch off from your problems as you play.
It also has physical benefits. An individual can play as demanding and gentile as they want to and their body allows. If a player has a physical issue that prevents other sports being played they may still be able to play Table Tennis. Obviously with caveats and risks assessed. During play the heart rate goes up and calories burned through aerobic exercise. Muscles in arms, shoulders, wrist, abdomen, legs are used and can be strengthened. If you get more serious about TT then other training such as weights and running can help your Table Tennis fitness, again all good for you.
Table Tennis is often recommended as a perfect sport for retired people. It will make such players move and use the heart but it is not as high impact on joints as other sports.
There is also remarkable footage of those who suffer from Parkinsons disease who are able to play Table Tennis which is a sport recommended for the disease.