hot pad vs table mat

hot pad and table mat both are nouns.

Word	Noun	Adjective	Verb	Adverb
hot pad	Yes	No	No	No
table mat	Yes	No	No	No

As nouns, hot pad and table mat are synonyms defined as:

hot pad and table mat: a pad for use under a hot dish to protect a table

hot pad (noun)	table mat (noun)
heater consisting of electrical heating elements contained in a flexible pad	a pad for use under a hot dish to protect a table
a pad for use under a hot dish to protect a table