A modern eating fork is a blunt fork. An older fork wasn't really a tool for eating from, but was really more like one of the large meat forks one uses to carve a turkey or otherwise hold meat. The tines were longer and there were often fewer of them. On top of this, they were sharpened to a point.
The difference is more like the difference between a sharp kitchen or steak knife and a dulled butter knife (even if it has a point). Sure, you can kill someone with the dull butter knife, if it doesn't bend and you hit the right spots, but it is going to be more difficult than the proper knife.