Compressed package covering FIC boards MY040 and PY640 at revision 0.3, presumably a shared schematic since the two codes are listed together. At about 1.38 MB it most likely contains PDF or similar diagram pages. Technicians use such drawings to trace power sequencing, find where a short sits on a rail and identify part values around regulators. Open the RAR with 7-Zip or WinRAR, then check which of the two boards you actually have and that the PCB revision matches 0.3, as layouts can differ between revisions.
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.