I have heard throughout my life that Asians ate monkey brains, that in fact, there were special tables designed with a hole in the middle through which a monkey's head can be inserted so that the brains can be consumed.
But after digging around a bit, I can't see an actual evidence that the consumption of monkey brains was a regular practice, or even happened at all. Is the practice of eating monkey brains just an urban legend or is there an actual historical basis for this?
there were special tables designed with a hole in the middle through which a monkey's head can be inserted so that the brains can be consumed
That's actually from a movie - Faces of Death, which was an exploitation movie (fake horror documentary) from 1978. This is the scene with the hole in the table you mention. NSFW, for obvious reasons, though of course it's fake.
The Indiana Jones movie "Temple of Doom" also has a banquet scene where they serve "chilled monkey brains".
I haven't come across any historical records of people eating monkey brains specifically. Bushmeat is popular in parts of the world, and no doubt monkeys are also eaten when caught. But it would be no different from people eating cow brains or sheep brains, there is no special contraption for trapping a monkey and serving it live at the dinner table.
Probably the stories with the special monkey cages and dining tables refer to the movie I mentioned above. I can assure you that the movie was fake. No monkey is killed or eaten; the brains are just colored gelatin.