Справка LibreOffice 25.2
Выделяет все записи, включая вложенные папки, в нижней части окна базы данных.
Selects the entire content of the current file, frame, or text object.
To select all of the cells on a sheet, click the button at the intersection of the column and row header in the top left corner of the sheet.
To select all of the sheets in a spreadsheet file, right-click the name tab of a sheet, and then choose Select All Sheets.