Zip archive of roughly 39.2 MB holding boardview data for a Dell board numbered 18718-1, with no further model information in the name. That numbering pattern is used by Wistron, a contract manufacturer for Dell. Boardview files show the placement of every part and the nets linking them, so a technician can find where a rail runs, probe test points and locate the component causing a short. Programs like OpenBoardView or FlexBV open common formats. Verify the PCB number matches before trusting the layout.
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 @laptexdna. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.