Zip archive of about 1.35 MB filed under boardview, but its generic name gives no model, brand or board number. Judging by the title it most likely holds a boardview viewer program rather than a layout for a specific board, though the contents can only be confirmed by opening it. Software of this kind is used to open boardview files and browse component placement, nets and test points during repair. Scan any bundled executable before running it, and check which file formats the included viewer actually supports.
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 @boardviews. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.