With a measurements table open in Multi-plot, select Multi-plot
Main->"Save data subset to file..." and the dialog below will
open. Select the data columns you want to save. Leave any extra
selection boxes empty and they will not generate a data column. If
you desire to include the column headings on the first line, enable
the checkbox as shown below. If you desire to include a '#'
character at the beginning of the first line to indicate a comment
line, enable that option as shown below.
Press OK and a file save dialog will open. Enter the desired path
name and file name and click "Save".