You can load a data file then merge another one into it, combining the two sets of space data intelligently - so if there is an overlap, SPACEWatch will update/add/remove files and folders as required, maintaining the accuracy of your analyses.
To merge a data file into your currently loaded data use the File - Merge option.
You might use this option to collect data automatically from remote locations using SPACEWatch command line options, copy the data files to your location, then combine them for comprehensive analysis. For more details on automating collection and command line options search for "batch" in the product Help.