Anyone please tell me what kind hinge (name of the hinge) used in this product?
Hinges


  what kind hinge (name of the hinge) used in this product?


That looks like simple pin (perhaps steel) in a drilled hole and a couple of spacers (perhaps plastic). I don't know of a specific name for this simple arrangement. Nor for the compound hinge formed by the arrangement of three simple hinges to form a folding brace.



Addenda ...



In the Snap-Jack furniture


  All the fittings, and hinges are stainless steel, and the magnets and keepers are nickel plated, the hinge spacers are plastic


So the hinges are basically exactly as I said above. The magnets are not part of the hinge itself.



Latches


  I think [...] a rare earth magnet [...] was used as a hinge


In the Snap-Jack furniture, magnets are not part of the hinge - magnets are used to hold the furniture parts in the fully-closed and fully-open positions. Magnets are also used to help hold the chairs and tables into the wall-mount in the stored position.


  Magnetic safety latches


These magnets are not part of the hinges.



Part names

All these parts are available separately from most hardware stores.


steel rod
steel or plastic washers (maybe spacers too)
disk magnets (screw mounted or epoxy into recess)
keepers (or use a steel washer and a short wood-screw)


I would use a drill-press with a table rotated 90° to drill the holes for the pins.