That's how they make paper and a lot of other flat goods like tape. The manufacturer makes these gigantic rolls then there's this entire industry called converting where a company, a converter, takes it and process it down into a finished product. They may add adhesives, lamination or printing to it during the process.

You can go to a store and buy 3M tape but 3M doesn't actually make it like that. They make a 12ft wide, 10,000 ft roll that someone buys and forklifts into a machine that cuts it into a bunch of smaller rolls that you can buy