The advantage of tables and chairs in a chic outdoor area is that guests have an appealing alternative to the indoor area at the same time. They are free to choose whether they want to enjoy the breeze and nature or sit comfortably indoors. In addition, as a restaurateur, you can expand your capacity with an outdoor area and accommodate more guests.
However, the outdoor area is particularly "weather-sensitive". Rain and wind are still the most harmless opponents - it gets really nasty when a biting cold comes along in the winter months. Even the toughest fresh-air fanatic will quickly buckle. Warming radiant heaters, for example, can provide a remedy.
In warm weather, however, other pests come into play: While the sun is shining, it's the wasps, and after sunset, it's the mosquitoes. This can hardly be avoided. However, to counteract bugs in the beer garden somewhat, you can have a few scented candles set up.