You misunderstood the comprehensive table. The answer to your question here is no. A lens marked as 50mm is a 50mm lens, regardless whether it is designed for FF or APS-C use. But, a 50mm FF lens will present a different FOV on a FF body vs. on an APS-C body. Both lenses are "real" 50mm lenses. That one of them is designed for APS-C is because that lens can be made physically smaller than is possible for a 50mm lens with the same aperture value made for FF use. While the 50mm lens made for FF use will work exactly the same way on APS-C as does the 50mm lens made just for APS-C use, conversely, the 50mm lens made just for APS-C will not work properly when mounted on a FF body because its optical elements are cut to smaller width for the narrower APS-C sensor, which will not be adequate for the wider FF sensor and will produce darkened edges of the picture The less-wide optics of the 50mm APS-C lens is not only more appropriately compact for the more compact APS-C body, but often saves cost as well.
Something not to forget- 50mm is a focal LENGTH- not width. It will have a different exit FOV as you look through it on different camera format bodies, including Medium Format- it just has to be wide enough for the format, or the format edges will not be included.
---------- Post added 01-26-20 at 08:12 PM ----------
First part of this already explained. A 50mm lens on a FF body is known as a "normal" lens, in that its FOV on this format is neither wide angle nor telephoto to any degree. So it is good as a versatile-use lens and the perspective of objects in a scene, are more normal, the front-to-back "look" is not elongated as would occur with a wide angle lens, nor compressed as would occur with a telephoto lens. But by putting the lens on APS-C bodies, which produces a narrower FOV, the image produced is akin to a telephoto effect- a narrower FOV than if it were on a FF body, so a smaller part of the picture fills up the frame. Therefore, not as versatile for all-around use. To get the same effect on APS-C you'd need to get a 35mm lens. There are some 35mm lenses available, both FF designs and smaller ones made for APS-C, some at lower cost and quite good.
The 50mm lens on APS-C, though not as versatile, has some other advantages. A moderate telephoto lens having a wide aperture of say f/1.8 on a FF body would be rather, or even quite expensive. The Pentax FA 77mm f/1.8 Limited comes to mind. With APS-C, one can get similar imaging in terms of FOV with a 50mm f/1.8 or a 50mm f/1.7 for a fraction of the cost of that Limited lens. (though in other respects, that particular lens has especially fine imaging properties). So for doing some very good closeup portrait work with excellent results, for example, one could go about this with fine results at far less cost using a 50mm lens on APS-C.
---------- Post added 01-26-20 at 08:27 PM ----------
By now you should know the answer. If you have a 50mm lens made for FF use, put it first on a FF body, then on an APS-C body, you will NOT have the same FOV, although both could use the lens. The APS-C sensor is smaller, so you'd get a narrower FOV. The outer edges of the wider-cut 50mm FF lens would not be included in the image. But if you put a 50mm lens made for APS-C on a FF body, its optical elements are not cut wide enough, so you'd get darkness around the image edges.
Of course, the same principle applies to wider angle also. For traditional FF format (35mm film), a general-use zoom lens of say 28-80mm, often a range used for kit lenses, but also some expensive f/2.8 professional style lenses, you would get a substantially wide angle-to moderate telephoto range. However, if putting that same lens on APS-C, a more telephoto effect being produced would also eradicate any wide angle use. 28mm on APS-C with a narrower FOV does not yield a wide angle FOV as it does on FF. This is why kit lenses for APS-C start at 18mm, as in 18-50mm or so. A pro-style f/2.8 aperture shorter zoom lens likewise will be 16 to 18-50mm and will be significantly smaller than the f/2.8 aperture 24-70mm or 28-80mm pro-style FF lens, and perhaps less costly.
A 35mm prime lens (made for FF use) on a FF body yields a moderate wide angle FOV, while on APS-C, with its smaller sensor and narrower FOV, it becomes a "normal" FOV lens, since the outer FF lens perimeter is not used.
