Whats the relationship between man and dolphin been like in ancient times and modern times?

Even in ancient times there were stories of dolphins carrying shipwrecked people to safety.  
The permanent smile on a dolphin's face makes people think they are friendly, which they sometimes are, but but the smile has nothing to do with it.
I've heard modern stories of dolphins playing with surfers in the waves.  They surf too!  And this is true, sometimes a dolphin comes close and a surfer grabs its dorsal fin and the dolphin swims off giving the person a ride!  If modern dolphins do this kind of thing, I'm sure ancient ones do too.
People have also killed dolphins for food; I imagine the dolphins aren't so friendly where people do this.  They aren't stupid. And dolphins have been killed accidentally by people fishing, and sometimes on purpose if the people think the dolphin is eating too many fish so the people can't get any.
Now I'll tell you my story, which almost makes me think dolphins are magic.  One time I baptized 3 children in the ocean.  It was an exciting occasion.  The moment they were all baptized, a pod of dolphins appeared close offshore and started playing around.  We followed these dolphins up and down the beach until they finally went back out to sea.

It depends on the culture.  In innuit culture, killing dolphins (Orca in particular) was a right of passage.  more kudo's went to the skilled hunter who brought down the biggest male. While the Mauri culture treated Orca's like gods.  

Native paupau culture in Peru revere the pink river dolphin  as sacred which is probably the only reason this extreamly rare species is still alive today.  

Ancient Greek cultures had a love hate relationship with the dolphin as you could understand given their time at sea.  Dolphins did compete with them for fish, but sailors told stories about being saved by them.  This carried into the Roman Empire (and we know they ate everything).  

Traditional Japanese culture is the same.  and the same can be said in New Guinea.  They still have hunts to limit the population of cetaceans in order to maximize fishing.