Although it might not be obvious why the Men of Numenor loathe Elf in The Lord of the Rings
Season 1, Episode 3, Galadriel, Halbrand and their companions are taken to Numenor's magnificent island kingdom more or less as prisoners.
The Numenorians greet them with open hostility. They also learn that Elendil was the captain who saved them at sea.
Later in the episode it is revealed that Elros, Elrond’s beloved Half-elven brother, was the first king from Numenr.
This further complicates the fractured alliance between these two peoples.