A lunchboxer is a guy who brings a lunch to work with him that his wife lovingly prepared for him with his favorite foods. A lunchboxer is usually a more mature knowledgeable worker in contrast to the generation x worker who eats week old dog food out of the vending machine in the truckers lounge just so his wife can get 10 more minutes of sleep.
Old Schooler: "This sure is a good salami and swiss sandwich that my wife packed me today!"
Irish Kid: " Oh quit being such a lunchboxer and showing off. I have to eat another one of these "Paulaburgers" because they are the only items left in the machine again!"