dinner napkin vs serviette

dinner napkin and serviette both are nouns.

Word	Noun	Adjective	Verb	Adverb
dinner napkin	Yes	No	No	No
serviette	Yes	No	No	No

As nouns, serviette is a hypernym of dinner napkin; that is, serviette is a word with a broader meaning than dinner napkin:

dinner napkin: a large napkin used when dinner is served
serviette: a small piece of table linen that is used to wipe the mouth and to cover the lap in order to protect clothing

Other hypernyms of dinner napkin include napkin, table napkin.

dinner napkin (noun)	serviette (noun)
a large napkin used when dinner is served	a small piece of table linen that is used to wipe the mouth and to cover the lap in order to protect clothing