That particular spot in CommuniCore/Innoventions West has housed a restaurant until recent years. From park opening until 1994, it was the Sunrise Terrace Restaurant. Once CommuniCore transitioned into Innoventions, it was split into Fountainview Espresso & Bakery (which is more or less still there, now serving ice cream instead) and Pasta Piazza Ristorante. Pasta Piazza closed in 2000 and sat there empty for a few years, just used every once in a while for things like the International Food & Wine Festival, until it became EPCOT Character Connection a couple of years ago and then redone into the EPCOT Character Spot that's there now. (Yuck.)
The rest of that quadrant has housed various exhibits over the years, Expo Robotics back when it was CommuniCore, and since it became Innoventions, the Walt Disney Imagineering Labs, the EPCOT 25th Anniversary Gallery, and of course Ice Station/Club Cool.