Like Jurist, I think most AE speakers wouldn't use packet for anything larger than a small flat envelope, usually containing a powdered mix of some kind, or indeed, sugar or sweetener. For example, seasoning for taco meat or spaghetti sauce comes in a packet, or you can buy instant hot chocolate, instant powdered soup, instant oatmeal, etc. in a box with several individual one-serving packets.
Potato chips, corn chips, and tortilla chips, however, come in a bag, and crackers and cookies usually come in a box or in a plastic-wrapped package.
In a general way, I think what leo029 is complaining about is serving ready-made, store-bought food to guests rather than making something homemade, and about offering a small quantity that may not seem generous enough.
leo, I'm just skeptical that this is solely a cross-cultural issue. It seems to me that there could be several other explanations for people's choices, and a range of choices, depending on the situation.
For example, if a group of guys get together at someone's house to watch a football game, I would think it would be entirely typical, and appropriate, for them to eat chips out of a bag (or out of a bowl) and drink beer straight from cans or bottles. I would also expect the guys coming over to bring at least some of the food and the beer, since the host is providing the TV (maybe with cable or satellite, which costs something) and has hopefully cleaned up his living room and vacuumed the crumbs and cat hair off his couch. Unless some of them really enjoyed cooking, I doubt that any of them, the guests or the host, would think it was worth the time and effort to prepare homemade food.
And certainly modern guys wouldn't expect a woman to do it all for them, right? The women, if they wanted to visit with each other while the guys were sitting monosyllabically in front of the tube, might just plan to meet at a café for coffee (or a sports bar for beer) anyway, and save the cleaning-up step. (-;
In addition to gender differences, some of it may also be age-related. College students eat almost everything straight out of the package; 30-something professionals who want to impress their friends and partners, or feed their kids healthier food, learn to cook. 70-something retirees, however, are often ready to go back to ready-made foods -- their backs hurt when they stand too long, it's too tiring to shop and cook for a group, and the women, especially, are often just tired of cooking, since most of their husbands in that generation never did a remotely equal share of kitchen work in their entire life.
There are also differences in people's food and drink preferences. If the host is himself on a diet or prefers not to eat too much between meals, or if he knows that some of the guests are overweight, or given to drinking too much, he might offer smaller portions for health reasons.
And there are differences in money, and people's attitudes toward money. Some people in all cultures are on limited incomes and can't afford to entertain lavishly. Certain people in all cultures may have an, er, less naturally generous personality, which is why most languages have words like 'stingy' and 'tightwad.'
I'm sure you're right that, even with those other parameters, culture also affects how people celebrate. A group of African men in Europe might indeed be willing to spend the morning cooking a big pot of stew or couscous or something before the football game, where German men wouldn't. Maybe there are even differences between German and Austrian men -- do the former make their own sausage and sauerkraut, and the latter make their own schnitzel and Sachertorte? (-: All I'm saying is that those may not be the only differences.