RAR archive titled M1330, a designation known from Dell XPS notebooks, though the name gives no brand, board number or revision. At 846 KB it likely holds a schematic or boardview for the mainboard. Use it to measure power rails, check the charger circuit and locate components when diagnosing a dead or shorted board. Since multiple board variants may exist, compare the ODM project code and revision printed on the PCB before working from it. Extract it with 7-Zip or WinRAR and view in an appropriate program.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @IT_SERVICE_WORLD. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.