In the Create tab you are able to access and work on invoices that may sit across multiple pages.
To work on these invoices in one screen:
Select the invoices you would like to work on by checking the box to the immediate left of the invoices. Once you have finished selecting the invoices you want on your first page, click to the next page you want to view and select invoices from.
Think of selecting the rows like you are "carrying" the selected rows with you as you navigate through other pages. Selected rows will appear on each page you navigate to.
Navigate to other pages and select other invoices you want to work on by clicking on the check boxes for each invoice.
All selected invoices will now be displayed in the tables on the right side. You can now merge, split, delete or create invoices from the pages that were originally located on different pages.