Hi Nick,
Yep, I know all about getting dizzy, but don't worry you get used to it. 
The query may run a long time if you have a lot of transactions and/or a lot of items and/or a lot of business partners. Also the longer the period (you have now set it to 2 years), the longer the query will run. And also a lot depends on your server hardware.
To get the results into Excel, just press the Excel button once the query has run.
Regards,
Johan