Page styles in Calc are applied to sheets. Although one sheet may print on several pages (pieces of paper), only one page style can be applied to a sheet. If a spreadsheet file contains more than one sheet, the different sheets can have different page styles applied to them. So, for example, a spreadsheet might contain one sheet to be printed in landscape orientation (using the Default page style) and another sheet to be printed in portrait orientation (using the Report page style).
Two page styles are supplied with Calc: Default and Report. The major difference between these two styles is that Report is portrait-oriented and Default is landscape-oriented. You can adjust many settings using page styles. You can also define as many page styles as you wish.
Because spreadsheets are primarily used onscreen and not printed, Calc does not display the page style on the screen. If you want a spreadsheet to fit on a certain page size, you have to carefully control the column width and row height, with only File > Page Preview to guide you.
Despite this limitation, it’s well worth defining page styles for any spreadsheets that you are likely to print. Otherwise, if a need for printing does arise, you may lose time to trial and error.