Yes, "immediate surroundings" means "nearest surroundings". It's because they're the places you can reach immediately.

Also, "immediate" can mean "closest" with respect to things other than time, in different contexts. For example: "Immediate family" (family that is most closely related), "immediate consequences" (the consequences that follow most closely), "immediate supervisor" (the person that supervises you most closely).

Yout immediate surroundings are the places you can reach immediately. Depending on the context this could mean things you could touch without standing up, things you could reach without driving your car, etc.