Archive for the Dell 7490, with F321P in the name and a service tag clear purpose, about 17.5 MB. It most likely contains a BIOS image or tool for erasing or resetting the service tag stored in firmware, typically used after a board swap. The contents are not listed in the name, so extract and inspect them before use. When editing firmware, read and back up the original SPI chip first, and check that the board you are working on matches the 7490 and F321P identifiers.
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 @cidschematicandboardviewofficial. 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.