While it is a little unusual to see it, open addressed tables can support multiple keys (as a set or associatively as a table). I believe most other collision resolution schemes can, as well. So, a Nim `Table` is what some people call a "multi-set". Whether you have unique keys depends upon the history of an instance.
When I was sprucing up the impls, I mentioned to Araq this might confuse some, but he said he uses this feature in the compiler proper. I think his was the right judgement call..Better to just inform about more than usual functionality when it comes up. To my memory, this is the first time it's come up 4 years. ;-)
