Many tools take a large number of options - for convenience, these are grouped together as Master Tool Settings so that you can save configurations of settings which you use often.
Use Options - Master Tool Settings to display the Master Tool Settings form, allowing you to modify or create settings for any of the categories.
Usually when you are using a tool which requires Master Tool Settings, you can either choose a setting name from the list, or use the button beside the list to make temporary overrides to the settings (if you have the appropriate user privileges).