The fact of the matter is, a router table is stone simple. It’s really just a tabletop with a mounting for the router, a fence to guide the work and some sort of stand to support the tabletop while you work.
Router tables turn the portable router into a precision stationary machine. Hanging under a table, they’re on standby for work, just the way your other tools are. Install a bit, adjust the fence, and they’re ready to cut.
Too, immobilizing the router in a worktable somehow makes it less intimidating, so you’ll use it more. And if it’s housed in a cabinet, its noise is muffled. Capturing dust is also easier and more efficient.
With that said, router tables can be expensive. It’s easy to drop more than a grand into a router table with an expansive top, a powerful router and lift, a sophisticated fence with micrometer adjusters and lots of attachments — plus a cabinet replete with bit and accessory storage, dust collection and its own electrical system.