unusual Danish folding table  

Can't help you with designer or manufacturer, but your table is referred as a convertible coffee table; ideal for tight living quarters. The hinge also looks to be quite old. I would guess Danish 50's for the piece, although I have seen similar brass hinges on Norwegian tables as well. Maybe that might help refine your search,

hi,
Thanks for the info, I will continue the search.
What about Borge Mogensen as the designer? I have read about his obsession for functionality in design.

Not Børge Mogensen. It looks nothing like his work. Also he is rather well known. if this were by a well known designer someone would have recognized it by now.
I would suggest you start by looking for other coffee tables identical to this one. If you are lucky, that will lead you to a marked one. Or perhaps a "made in Denmark" or Sweden or Norway or possibly a few other places. And if you are lucky some research into the company will lead you to a designer. Although it is entirely possible that it is a generic piece also.