Sometimes it is useful to preview more than one page at a time.

1. A simple approach could be to add "Show multiple pages" option and if it's set display more pages if zoom level allows for that. Similar to Okular's Overview View mode. (Okular limits this to 3 pages though). See the attachment.

2. Another option is to offer exact number of pages as a zoom option: instead of single page user sets e.g. 6 pages so they are all displayed. 

2.1. Consider displaying the pages not necessarily in a row, i.e. instead of displaying 6x1, display 3x2.

Note 1: If Fit Width option is present and set, all the pages (e.g. 6 pages) should have maximal zoom and fit on the screen.

Note 2: If Continuous pages option is set, the display should apply this (see the attachment).