The garbage disposal was invented in (I think) the 1920s for restaurant/commercial use. At the time, it was a hand-cranked meat grinder thing that sat on the drain board. The operator would grind the food into the sink and flush it away with water.
The first microwave ovens came out in the 1950s and were called "electronic ranges." They were big wall ovens, and home ec books of the period show girls using them to bake cookies on sheets of cardboard. These ovens were enormously expensive. The first countertop microwave was the Amana Radarange circa 1967. Still, it wasn't until the late '70s that microwaves really caught on with consumers.