Curious babies are great, but during meals distractions are not such a good thing. An old Commodore 64 or Amiga 500 could drive the television directly, and receive data through a serial cable. I rejected this option because of the space required, and because of the energy required to drive yet another computer in our house. Various manufacturers offer VGA cards with composite output. I rejected that option because of the expense, and because of our strong environmental preference to avoid purchasing new equipment when possible.
Modern computers require a tremendous quantity of toxic materials in the manufacturing process.
I would have tried this option, but I was not able to locate a secondhand dongle and, again, did not wish to purchase a new one. I located a VGA to composite black and white video adapter circuit designed by Tomi Engdahl. This circuit calls for only a handful of resistors. I assembled the circuit on a Radio Shack prototyping breadboard. A good composite video connection requires a 75 ohm cable.