According to Official Guinness Records,
The most participants in a table tennis rally is 139 and was achieved during the Kyowa Kirin Four-prefectural (Iwate, Miyagi, Fukushima, Ibaraki) Kizuna Table Tennis Friendly Match (Japan), held in support of the Tohoku Region, in Inawashiro, Fukushima, Japan, on 27 April 2014.The participants were elementary, junior high, and high school students who belong to the table tennis associations of the four prefectures, as well as adult table tennis players who coached them for the duration of the event.
For a complete list of 2014 records, please visit 2014 Guinness Records in Japan.