Looking for a smart program to aggregate all my .dat files.

We do not provide a utility like that, and I'm not aware of a single utility/app specifically like you are mentioning. There are tools and commands for joining files, and then in Excel import as a csv file and manipulate the data.

For LJLogM log files, you could look into a join utility, import into Excel and sort rows by the first column's timestamp. With Windows command line, there is the "type" command that displays file text, and can be used to join files. For example, move dat files made with LJLogM to their own folder. Then by command line go to that directory (the "cd" command) and run this "type" command which basically displays all the files' content ("*" is indicating all files) and outputs it to file the file "all_log.dat":

type * > all_log.dat

For LJStreamM, for a single log session with multiple files you can you can merge files but you will need to delete the header information with the date, time, etc. that each file had. You will want the first header for your start time. For multiple stream log sessions, to combine all that data will be more involved as you need to modify timestamps to a global time, which can be based on the start time.