RAR archive labelled only K54, a notebook model designation; the name does not say whether it holds a schematic, boardview or firmware, nor which board revision is covered. Extract it with WinRAR or 7-Zip and inspect the contents before use. Material for this kind of laptop typically serves for tracing power sequencing, locating components and test points, or reflashing the BIOS chip. Always check that the board number and revision printed on the PCB match the documentation, and back up any original chip before writing a dump.
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 @alischematics. 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.