Complex sentence: In professional settings massage clients are treated while lying on a massage table, sitting in a massage chair, or lying on a mat on the floor, while in amateur settings a general purpose surface like a bed or floor is more common.
Split into simpler sentences: In professional settings, clients are treated while lying on a massage table, sitting in a massage chair, or lying on a mat on the floor. In amateur settings, a general purpose surface like a bed or the floor is more common.