tabulating machine vs tabulator

tabulating machine and tabulator both are nouns.

Word	Noun	Adjective	Verb	Adverb
tabulating machine	Yes	No	No	No
tabulator	Yes	No	No	No

As nouns, tabulating machine and tabulator are synonyms defined as:

tabulating machine and tabulator: an electromechanical machine designed to assist in summarizing information and, later, accounting.

tabulating machine (noun)	tabulator (noun)
an electromechanical machine designed to assist in summarizing information and, later, accounting.	a calculator that keeps a record of the number of times something happens
	an electromechanical machine designed to assist in summarizing information and, later, accounting.