Can you tell me how to activate the Multiple Operations mode (under options) in Libre office calc. Currently I have no access to the function (shade grey)
You mean menu Data and there item Multiple Operations? That is a wizard, which needs a special way for the arrangement of the data on the sheet. Please read the section “Applying Multiple Operations” in the build-in help.
But you do not need to use the wizard, but you can use the function MULTIPLE.OPERATIONS as any other function. Its purpose is to fill a cross tabulation based on an example calculation. The wizard only helps you to set the $ for absolute references at the correct place.
Is there something special, which you want to solve? Or are you only curious about this tool?