In the Pacific Northwest, all of those bent blades are called "crooked knives."
However, the PacNW style is surface-hafted, sometimes tilted a little (I do all at 10 degrees) and the handles are anything but round, often with a tapered end to the handle.
The Scandanavian style is center hafted with commonly a round handle.
It's OK to call them all "spoon knives" but that sort of denies their versatility for carving all sorts of things besides spoons.
The third sort of design is based upon the stone-age blades used in eastern North America. It, too, is called "crooked."
These people might be grouped together by their extensive use of birch trees fo many different constructions.
The blade has a sweep at the tip, the home-made ones are all different. The blade may be tilted a little and it may not be aligned with the axis of the handle.
The thumb notch and often additional carvings are characteristics, also.
I should finish one of these "Mocotaugan" style knives in a week or two.