Don't stress out... I know it is a bad habit but since the child already is used to it it will take little time... Initially my son also did the same thing but with some effort I have finally helped him to have meals with out any gadget. I started to offer meals only when he was hungry, tried to make sure that we have meals together, initially I gave mobile then slowly I started to off the internet or cable and showed him there is no connection. Got colourful plates and spoons with cartoons, made food attractive... Try to include the child in family meals.. This works well... Last of all you need to keep a lot of patience as it takes some time to see the results... Happy parenting 😊