The Tools multi-function button is particularly helpful, if the PKIN tool is opened as an intermediate dialog and hence has no menu available. In this case, Save KM, Save Par, Append Par just allow to save the data as a .km file, as a parameter summary text file, and to append to a latter file.
View Par opens a dialog window and shows a quick summary of all regional model parameters as well as the statistical criteria, see above.
Edit Data allows editing/processing the data values and generating new TACs, for instance by averaging TACs or adding noise, see below.
Edit Patient allows changing the demographic patient data as well as the radionuclide, see below.
Comments opens a dialog window for entering arbitrary comments, see below.