Basically, the answer is yes, if the lunch is light and does not contain alcohol
Google Taxation “Ruling IT 2675” on the ATO website for more detail or read on.
Taxation Ruling IT 2675, states that the more elaborate the lunch becomes the more likely it is to be deemed entertainment and there will be issues with both deductibility and Fringe Benefits Tax.
Taxation Ruling (TR) 97/17 Entertainment by way of food or drink, asks that you consider 4 question.
1. Why is the food being provided?
2. What food is being provided?
3. When is the food being provided?
4. Where is the food being provided?
Answering the above will help you determine whether or not the food and drink being provided is for refreshment and sustenance or entertainment.
It’s worthwhile mentioning that TR 97/17 states that having a lunch at a café with a client does not make it entertainment, but it is more likely to be so when compared to having the lunch at your place of work.