There are a number of food items people eat that are not safe or healthy for pet parrots. 

Never feed:

Avocado (including avocado oils)

Chocolate (dark, milk, and white)

Garlic and onions

Mushrooms

Fruit seeds/pits

Alcohol (beer, wine, spirits)

Salty/High Sodium Foods

Dairy/Milk/Cheese - safe but birds cannot digest lactose which can lead to diarrhea 

Butter and margarine

Caffiene (coffee, tea, sodas, energy drinks)

Meat (beef, chicken, pork, etc.)

Bacon or Other Animal Fat

Animal byproducts

Junk Food (potato chips, corn chips, french fries, Cheetos, pretzels, etc.)

Human Medications (prescriptions or over the counter)

Illicit Drugs (Cocaine, Marijuana, Crystal Meth, etc.)

Ornamental Houseplants

Peanuts - risk of fungal toxins

To find out what foods are safe to feed your bird, click here: Safe Treats for Parrots