It should be based on what it weighs plus what it can carry (payload) safely, including stopping and adequate performance for going.
I believe the amount a TV's axles can "carry safely" usually is considered to be covered by the GAWRs.
And, I believe the "adequate performance for going" usually is considered to be covered by the GCWR.
That would leave the GVWR to cover "stopping" safely as defined by
FMVSS Standard No. 105; Hydraulic and Electric Brake Systems and
FMVSS Standard No. 135; Light vehicle brake systemsRon
