When selecting "import data " to import my selection, I only get two options import data and generate script. How do I get the third one, "generate function"

I am importing data from excel spreadsheets and there is supposed to be a means of selecting a few columns then when you click on "import data" you are supposed to get three options: "import selection" (which I usually use), "generate script", and "generate function". Sometimes I would like to generate a function but this option doesn't appear on the drop down menu, I just get two. Does anyone know if this is a bug or for some reason some platforms cannot do this? If not, why not? I am using a Mac with Safari and version 2014a Matlab.