Brieftons Express Manual Food Chopper: 2-Cup, Hand Chopper Vegetable Cutter to Chop Veggies, Fruits, Herbs, Garlic Onion Chopper for Salsa, Salad, Pesto, Hummus, Guacamole, Coleslaw, Indian Cooking

Q: How well does this work on onions?

You have to cut the onion into a few pieces first, preferably uniform size. Then it works great! Push down a few times for slightly chopped, more times to get smaller size chopped onion.

Q: Three plastic blade with product is to be used or thrown away? I see the silver blade, but plastic blade used for protecting silver blade?

Yes the plastic cover is a finger guard for the stainless steel blades only. It is not a blade and cannot be used as such. I hope it helps!

Q: Will it chop eggs for egg salad?

I haven't used it for chopping eggs, but I don't see why it wouldn't work. It is a powerful chopper so you will need to check the consistency after each spin so you don't wind up with mush. It will definitely do a great job on the celery on onions.