tablet vs electronic computer

tablet and electronic computer both are nouns.

Word	Noun	Adjective	Verb	Adverb
tablet	Yes	No	No	No
electronic computer	Yes	No	No	No

As nouns, electronic computer is a hypernym of tablet; that is, electronic computer is a word with a broader meaning than tablet:

tablet (noun)	electronic computer (noun)
a dose of medicine in the form of a small pellet	a machine for performing calculations automatically
a small flat compressed cake of some substance
a slab of stone or wood suitable for bearing an inscription
a portable computer with a touchscreen
a number of sheets of paper fastened together along one edge