Austria does not have as strong a business entertaining culture as some other, more southern European cultures which reflects the strong separation which is often made between work and private life.
Thus, it is fairly unusual to be taken out for dinner and even rarer to be invited to someone’s home. Most business entertaining is done over lunch — usually at a good restaurant. (Breakfast meetings are extremely rare in Austria.)
During a business meal, it is possible to talk about business, but it might be wisest to delay introducing work related issues until the host raises the matter.
If invited out for a meal, the host will always expect to pay. Similarly, if you invite someone for a business lunch, you will be expected to pick up the bill. In Austria, both the knife and fork are used throughout the meal. Eating with only one hand, with the other hand placed on ones lap under the table, (as is common in North America) is not considered particularly good table etiquette.
Alcohol will usually be offered at lunch and dinner but many Austrians will refrain from drinking at lunch time. It is probably best to take your lead from your host.
It is quite usual to tip in Austria. A tip of around 10% should be given directly to the waiter at the end of a meal.