You can add as many Expenses as you want to one invoice, but you will have to create an separate expense for each item.
We had a request from another user for a "batch" function, where you would enter the Client, Project, etc. then you would add multiple expenses to it. We are considering this idea. When finished, it would then create all the individual expenses. We're not sure if that is the way we will go yet, but could be a big time saver for people who need to add multiple expenses in one shot.
