What does the expression «to poison tales» mean?
If someone tells you stories that aren't a single word of truth, they're “травит байки” (“travit baiki” or “poisoning tales”).
The word ‘travit’ has several meanings in Russian. These days, it means ‘to poison’, but it also used to mean ‘to tell a lie’ and ‘to feed’. ‘Baiki’, in this case, are tales or stories. So, "travit baiki" (literally, "to tell tales") means, figuratively, to feed someone a lie.