FYI, the new v2.5.0 includes improvements for spreadsheets (xlsx etc.):
var inputOptions = new SpreadsheetInputOptions
//Only visible sheets
OutputSheetRange = new SheetRange("visible"),
//All columns of a spreadsheet should fit to the same page (do not break)
RenderColumnsFitToPages = 1
//All rows of a spreadsheet should fit to the same page
RenderRowsFitToPages = 1
//All rows of a spreadsheet should fit to 2 pages
//RenderRowsFitToPages = 2
DocumentUltimate.DocumentConverter.Convert(inputDocument, inputOptions, outputDocument);
For example if you set RenderColumnsFitToPages to 5 and if you have 50 columns then you will get 5 pages with 10 columns on each. When RenderColumnsFitToPages set to 0, it means it’s not limited and the columns may be broken into many pages as required. Usually the most useful setting is 1 because this way, all columns will be on the same page and you can always pan and zoom in the viewer.
For your specific question, you would be interested in RenderRowsFitToPages, for example if you set it to 5 you will get 5 pages for the whole spreadsheet.