In the 1950s, not everyone had a TV, so it was not uncommon to find 10 or so people gathered around one set. So how would they eat those marvelous TV dinners? Early frozen meals came in trays made of aluminum -- a metal which conducts heat really well. People couldn't just set them in their laps, unless they wanted to risk getting burned in a particularly painful way.
Fortunately, a solution already existed to that dilemma. Folding tables had probably been around for a long time, but in 1946, a Los Angeles inventor named Henry V. Gaudette applied for a patent for a new, improved version, with rotating legs that could be anchored in an X shape under the tray. Not only was that configuration more rigid and stable than previous folding tables, but when the table was collapsed, it was completely flat, which made it easy to store [source Gaudette].
Gaudette's invention was ideal for eating while watching TV, and by the early 1950s -- even before Swanson introduced the TV dinner -- cheap metal versions of the folding tray table were being advertised in newspapers. A 1955 ad in the St. Petersburg Times touts a TV snack table, offered for a bargain price of $1.67, that was "ideal for your TV guests" and came in a stain-resistant enameled design with a choice of three decorative patterns [source: St. Petersburg Times].