Using Telerik HTML5 Report Viewer Page R3 2018.
When designing the report in the designer and viewing it on the html page, the tables are fine. See capture1.png.
But when downloading the page to pdf, the tables get clipped horizontally so that only half the columns show on one page and the remaining get pushed to a subsequent page. So the number of pages increase in the printout. See capture2.png and capture3.png.