Samsung has a pretty vast library of available tablets out there, some running Android and others running Windows. The point being, they have quite a few different options to choose from. The tablets also range from sizes of 7-inch screens all the way up to 12.2-inches, but nothing so far has been produced by Samsung with a screen larger than that. This could change sometime in the future though as it seems a new Samsung tablet has been spotted, or rather a listing for a new Samsung tablet, that carries an extremely massive 18.4-inch display which is easily larger than anything they've ever put out.
It's worth nothing that so far no image leaks have popped up showing what is thought to be the tablet itself, what has shown up is a listing of the tablet in question that it's currently being tested. The listing clearly states that the device is a Samsung tablet, and in parenthesis it states "S.S - 18.4" which would stand for screen size, and the actual size of the display in inches. It's also listed as only being for testing and evaluation at this point so there's no telling if the tablet will even make it past a testing phase and if it does, when exactly that would potentially be.
According to the leak the tablet is valued at about 32,371 Indian Rupees, which equals about $507 USD. Having said that, if Samsung were to manufacture this tablet it wouldn't necessarily keep this value and could end up being less or more, but given the size of the display and depending on what type of screen technology Samsung used, it could go either way. As most consumers probably wouldn't be interested in a tablet this big, it's likely that Samsung would aim this tablet at businesses and possibly government where it could be used for things like conferences or demonstrations. It could also be a great device for families though who have multiple people who might want to engage in use at the same time for things like multiplayer games or watching movies. All of this is irrelevant however, since there's no confirmation this tablet actually exists or that it will end up in mass production and finally released.