A boardview (component placement) file (board LA-7731P). Shared as “QAM00 LA-7731P (REV 1 (1).0) (A00) (BDV).zip” — a .zip file, 294 KB.
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 @schematiclaptopramkushwaha. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Built-in OS tools7-Zip