The story
Uncertain, but probably a generic name like Jane, in reference to the device replacing a servant at table. The earliest attestation is from c. 1903 in the Boston Journal, which credits a local carpenter named John Laurie as "the resuscitator of 'Lazy Susan'". Almost certainly not named in honor of the daughters of Thomas Jefferson or Edison who were both named Susan.
Etymology from Wiktionary, CC BY-SA 4.0.