Start with the table laying flat, top down.  Locate the legs and screw the threaded rods into the sockets.  No need to overdo it.  Finger tight is enough.  Position the legs at the table corners.  Place washers, lock washers and nuts on ends of threaded rods - do not tighten.  Now fit the other elements to the frame.  The blind screws are ***frustrating***,  The long horizontal may appear short - push the legs together.  THEN tighten all connections.  It looks good once in place.