No, at the moment, it is not possible to request a monthly invoice that includes all the purchased services.
However, Packlink PRO will soon be launching a new feature that will allow users identified as Business/Freelancer and who have provided their TAX ID number in their Invoice Details, to receive their invoices grouped into a single monthly document.
Once we have implemented this feature, we will inform you through the 
Notifications panel of your PRO account, so that you can activate it and enjoy this advantage.
In our Help Center we explain how to access notifications about new PRO features and how to update your invoice details.