They are more or less interchangeable.
However, it is for some prople seen that two friends "taler" while two business companions "snakker". So "taler" is more personal whereas "snakker" is a bit more professional. This is only a small detail and not something that is widely used in practice.
'At snakke* is a bit like 'to chat' while 'at tale' is more formal like 'to speak'. "Papegøjer snakker, mennesker taler" (Parrots talk, people speak).
DL har aldrig forstået dette!