How Old Should Kids Be Before They Use A Knife Alone?

Not alone as in being off in a room alone with a butcher knife . I’m just wondering at what point I should stop cutting the kids’ dinner foods and let them give it a go themselves. And I don’t mean a sharp steak knife or anything – it’ll be a while before I let them at the plasma cutter too – just the regular table knife. I guess it just depends on how coordinated they are. Matt uses one for his pancakes now but I’ve not ventured any farther. What guidelines do you use? Do your kids use table knives yet?