One is tempted to parody Shakespeare: “Who was Susan? what was she?”
All that we have learned is that this “Susan” appeared on the American scene perhaps seventy-five years ago and probably in New England.
She, or rather it, was the successor of the dining-room article which, in both England and America, had been called a “dumb waiter.”
This device, known since the mid-eighteenth century, usually stood alongside the host, its three shelves, laden with wine, rotating about a common spindle.
Presumably, the presumption being entirely mine, in some American family this silent servitor replaced a living, energetic, and anything-but-dumb waitress.
In ironic honor of her activity, let us say, they called it lazy Susan.
We can readily assume that the name would remain when, as a matter of further convenience, the shelves were reduced to one and the shortened device was lifted to the center of the dining table.