Archive marked BOTTOM for the Compal motherboard LA-A101P, most likely an underside placement or layout view, paired with a TOP file of identical size. Bottom-side drawings are useful for finding capacitors, test pads and small components hidden under the board when measuring rails or isolating a short. The LA- prefix with a P suffix is Compal's board numbering scheme. Check the board number and revision silkscreened on your PCB match before trusting the layout, as revisions may move parts.
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 @SCHEMATICWORLD. 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.