Another option could be to utilize Pivot Tables.
I used to run queries for a company previously that would return 100,000+ rows of data. Sometimes you have to get creative. Unless there is a true reason behind keeping the tabs for Sales and Inventory separate, you may want to combine the 2 together. Looks like you have similar data contained on both. I would then insert another column, such as, "Type" or something of the sort. Identify the rows accordingly 'sales' vs. 'inventory' data.

Then utilize the Pivot Table function to summarize the data. It presents really well, and is very simple to use. Just have to get the hang of setting up the table itself.

Bob- do you think that is also a viable solution as well?