I grew up eating pretty much anything, so liver, kidney etc are all on the "yum" list.
My grandmother cooked tongue and I could never quite get my tastebuds to work with me on that one...usually eaten very heavily hidden in my mashed potato! I was rather confused as a child however as one of the flat fish is called "tongue" in Swedish, so I was never sure which they were serving til I got to the table...
Sweden has some interesting foods which I always enjoyed (and was usually the only one going for seconds at school when they served), including pölsa-which is nothing like the Norwegian pølse which is just sausage. Pölsa is the closest equivalent in content to haggis I guess, but closer in consistency (and colour) to gruel. Served with pickled beetroot of the sweet non-vinegary variety. Yummy!
It is apparently known as "lungemos" (mashed lungs) in Norwegian!
We also do a form of black pudding (called blodpudding-blood pudding) which is delicious with lingonberries.
I have eaten sheep's brains once. I prefer not to repeat the experience as the texture made me gag. Ditto oysters and snails, on a slight tangent-they're just a bit rubbery for me!
For reasons unknown, I haven't actually had heart, tripe or sweetmeats/breads (I can never remember which is which but haven't had either). I do have a slightly guilty penchant for foie gras though, which I learned to adore long before I knew the animal welfare issues! I'd happily learn to kill, skin and eat my own food and am entirely unsqueamish about where it comes from. Venison, elk and reindeer are all on my "happy to eat" list too