While it is very therapeutic to watch a train rolling around a loop of track, many model railroaders choose to move on to bigger and more complex track arrangements by building a model railroad they can run as if it were a real-life one serving businesses along their lines as well as moving mass commodities like unit coal or grain trains. In essence, such a model railroad becomes a 3-D game set on a colorful game board you can simulate “railroading for real” on.
Often you can read of model railroaders with basement-sized layouts who host regular “operating” sessions where a group of friends gather to operate the railroad like a real one, dispatching trains, running them, etc. Some are so into it, there is a separate room nearby dubbed the “crew lounge” with a TV and some chairs for “off duty” crew to relax in. (Though, frankly, I think having a TV present defeats the purpose of relaxing with model trains. TV can be so hyper it can cause stress levels to go sky-high, but I digress.)
But you don’t need a massive train layout to have fun “operating” a railroad. On a four by eight tabletop pike you can put in a couple spur tracks off the “main” you can switch cars on and off of at, say, a warehouse, or grain elevator, or whatever business that strikes your fancy that you can fit onto the tabletop. Having once practiced with wooden Brio trains the art of operating such a model railroad design, words fail me when it comes to describing how fun it is!
In my opinion, the most ideal sort of model railroad is one that allows you to watch trains roll by round and round as well as has businesses along them that ship by rail you can stop a freight train at and play a 3-D game of, say, switching tank cars “way billed” for “Western Oil” or cars for some other make-believe business; it will give you many relaxing hours of model railroading enjoyment.