Gelatto Splatto is a ice-cream store/ice-cream parlour in Grand Theft Auto: San Andreas. It operates a single store located in Santa Maria Beach, Los Santos in 1992. It is never directly revealed in-game exactly what the store offers but a clue can be found in its name. Gelatto is a misspelling of gelato, which is a type of Italian ice cream, so it is implied that Gelatto Splatto is in fact an ice-cream store or parlour.
The store/restaurant does not play a role in the storyline and is inaccessible.