"high in stature," 1520s, probably from Middle English tal "handsome, good-looking; valiant; lively in speech; large, big; humble, meek," from Old English getæl "prompt, active," from Germanic *(ge)-tala- (source also of Old High German gi-zal "quick," Gothic un-tals "indocile"). Main modern sense "being of more than average height (and slim in proportion to height)" probably evolved out of earlier meanings "brave, valiant, seemly, proper" (c. 1400), "attractive, handsome" (late 14c.).
Sense evolution is "remarkable" [OED], but adjectives applied to persons can wander far in meaning (such as pretty, buxom, German klein "small, little," which in Middle High German meant the same as its English cognate clean (adj.)). Meaning "having a (defined) height," whether lofty or not is from 1580s. Meaning "exaggerated" (as in tall tale) is American English colloquial attested by 1846. Phrase tall, dark, and handsome is recorded from 1906. Related: Tallness.