At the upper position, the tabletop units 32 are separated and the brace portions 38 and 40 are disposed in substantially axial alignment or in substantially a straight line, and {HEAD ~ the tabletop units} 32 are at {TAIL ~ higher tabletop position} 
are at
At the upper position , the tabletop units 32 are separated and the brace portions 38 and 40 are disposed in substantially axial alignment or in substantially a straight line , and { HEAD ~ the tabletop units } 32 are at { TAIL ~ higher tabletop position }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL