RAR archive of 6.88 MB for the Lenovo IdeaPad 3 15ITL6; the name gives only the model, with no board number, revision or content list. Packages for this model usually hold a schematic, boardview or BIOS dump, so open it with 7-Zip or WinRAR to see what is actually inside. Lenovo IdeaPad boards are commonly designed by LCFC, but check the board number silkscreened on your PCB against any document in the archive before using it to trace rails, locate parts or reflash firmware.
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 @ShareMan_Electronic_Files. 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.