What unusual technological devices are there in "The Veldt"?

Most of the technological innovations in "The Veldt" sound great at first. But once you realize that they're replacing human relationships and actually reducing adults to the level of helpless children, then they don't seem like such a good idea all of a sudden. A kitchen table that actually cuts your bread for you sounds like the ultimate labor-saving device, the kind of thing you'd see on an infomercial. But the problem is that, if something goes wrong with the technology—and technology always breaks down at some point—then you're in big trouble. It's no exaggeration to say that if all the appliances in their super-deluxe kitchen that do everything for them end up on the fritz, then the Hadleys could practically starve to death.
In some ways, then, the children's nursery, with its ultra-realistic lions, is simply the ultimate example of the many dangers inherent in all the various technological devices arrayed around this bright, shiny Happylife Home. Even if the Hadleys had not ended up as breakfast for the ferocious beasts of the veldt, it's likely that, sooner or later, they would've met their unfortunate ends at the robotic hands of one of their labor-saving devices. If the bread-slicing table had gone haywire, for example, the consequences simply don't bear thinking about.

Ray Bradbury's "The Veldt" is centered around technological advancement and wild inventions. The story's two most obvious unusual technological devices would be the nursery and the HappyLife Home.
The nursery can turn itself into any setting the children can imagine. The nursery can recreate the sounds, smells, and sights of whatever things the children choose to imagine. As George and Lydia note many times throughout the story, the nursery and its scenes feel very real. Unfortunately, the nursery can also be dangerous and eventually takes over as the parent of the children. 
The HappyLife Home is composed of a variety of strange - and very cool - technological devices. Inside the HappyLife Home is a table that makes food for the homeowners, a machine that ties people's shoes, machines for cleaning the house, machines for giving people baths, etc. The HappyLife Home ensures that homeowners never have to lift a finger or complete a domestic task without assistance. The HappyLife Home sounds great in theory, but in actuality it makes the homeowners feel useless and unneeded.