Holy shif! These are Nintendo's special cartridges for the Super Famicom Box system, a relatively rare variation of the Super Famicom that was built specifically for installation in Japanese hotels in the mid-90s. The main cartridge—with Super Mario All-Stars, Super Mario Kart, and Star Fox on it—also contains the special operating system for the unit itself. The Super Famicom Box itself can accommodate two cartridges, the first of which is always the aforementioned one, and the second of which is an option cartridge. My second cart here slides into the bottom port. This particular one has Donkey Kong Country and Tetris 2 + Bombliss, meaning you have a pretty good selection of games right there on it. A couple other cartridges exist, one with a Bomberman game and another with a mahjong and golf game on it, but I think the two cartridges I have here are probably the best two.
How big are they exactly? In the basic footprint of a Super Famicom Box cartridge, you could fit twenty-eight 3DS games. Some might argue that certain enclosed arcade PCBs count as "cartridges" and might actually be larger in a sense, but I think these must be the largest carts devoted to console titles and not arcade hardware.
In operation, the system was usually hooked up to a hotel room television and funded through a right side panel to an external coinbox that added game playtime credit. Others were likely configured for free play (perhaps in love hotels and other "full-service" establishments). There's a plastic cover that blocks off the coinbox expansion slot in that case. The unit itself is operated by way of a keyslot in the lower right corner, with multiple possible positions, each one of which enables a different function (basic operation mode, service/statistic mode, diagnostic mode, and a demonstration mode, in addition to just plain off).
None of these things were ever for sale via retail channels, officially. Most of the existing units were sold off by hotel chains in the late 90s, and passed into the hands of various consignment shops. I bought mine off an outfit from all the way up in Hokkaido, which had so many of them that they were selling them in stacks and paid the shipping just so I'd take it—no mean feat considering the absolutely absurd weight of these units. (I checked, and mine weighs in at a whopping 22 POUNDS (10.1 kilograms for you rest-of-the-worlders)), slightly more than my gonads.
Even though the Super Famicom Box is somewhat well-known in collector circles and among Nintendo votaries, many people who know about the system haven't ever actually seen inside one. The two barrel locks on the front are essentially unopenable without the original keys, which are almost never still in the vicinity of these old systems. Without the keys it's tough to get inside, though my gamebit security screwdriver made quick work of the bottom hinges, and from there it was an easy-enough fenaggle to tilt the front off and expose the juicy insides. I rendered the operations keyhole "keyless" by taking it apart and removing the lock tumblers, so basically any key that fits in it will work. I also cranked the barrel locks to the side so they don't latch shut—a couple thin magnet strips applied to the top keep it closed now. Short of getting a locksmith to custom-machine brand new barrel lock keys for the thing or replace them entirely, there aren't many other options unless you're willing to alter the system from its "factory state."
Another unique element of the Super Famicom Box is that the controllers have extra-long cables. The model numbers of the controllers are the same as the normal ones (SHVC-005), and they actually are identical to the original ones except for the extra-long cables connecting them to the inside of the unit itself. If you were so inclined you could even just detach the controllers from their plugs in the Super Famicom Box and use them on a normal Super Famicom to play a game without needing to sit three feet from the TV.
Perhaps the only real downfall of the Super Famicom Box, aside from its completely absurd size and weight, is the fact that there is no way to play actual Super Famicom cartridges on it. Nope, you're locked into the same handful of games forever. The video output via the back uses standard AV cables, and looks and sounds really clean on a television I should note! But yep you are playing Mario and Star Fox till the end of your days, prospective SFB owner.
When I die, if I still have this, I will request that someone ties it to my legs and drops me into the ocean, so that it can immediately pull me to the seabed and I can become one of those habitats for fish like old lockers or whatever they're straight up dumping into the ocean these days.