Because in Esperanto language, if you wave greetings to someone, you must use the accusative case with "-n". It's like "Bonan Tagon" or "Feliĉan Naskiĝtagon". It looks hard but it's easy :)

The word Saluton seems to be Saluto in its origin, why did you add "n" at its end?

Saluton! Jes mi parolas esperanton.

Saluton! Jes :)