Tamaki actually has two names, Suou and Rene Tamaki Richard Grantaine as revealed in chapter chapter 55. The name Suou can be translated to "rightfully becoming king" or "to become a king"(from wikipedia), and this name fits him very well since his personality matches perfectly. Tamaki knows he's good looking and opening calls himself king, plus he's french. Bounus! He's like this gorgeous Japanese French King.

In the english VIZ Media verision of the manga Tamaki's last name is changed to Suoh, his original Japanese name is Suou though. Both names are widely known, if you haven't guessed by now I perfer the Japanese way(Suou).