Old English talu "series, calculation," also "story, tale, statement, deposition, narrative, fable, accusation, action of telling," from Proto-Germanic *talō (source also of Dutch taal "speech, language," Danish tale "speech, talk, discourse," German Erzählung "story," Gothic talzjan "to teach"), from PIE root *del- (2) "to recount, count." The secondary Modern English sense of "number, numerical reckoning" (c. 1200) probably was the primary one in Germanic; see tell (v.), teller and Old Frisian tale, Middle Dutch tal, Old Saxon tala, Danish tal, Old High German zala, German Zahl "number."
The ground sense of the Modern English word in its main meaning, then, might have been "an account of things in their due order." Related to talk (v.) and tell (v.). Meaning "things divulged that were given secretly, gossip" is from mid-14c.; first record of talebearer "tattletale" is late 15c.