Toshiba repair archive of 15.1 MB referencing MDK MB-17 W and 1402-5, likely a board project label and revision code, though their exact meaning is not given. No laptop model is stated, so match the markings on your mainboard with the documents before use. The zip probably holds a schematic and possibly a boardview or firmware; check by extension after extraction. Schematics serve for tracing power rails and signals, and any BIOS image should only be written after reading out the original chip.
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 @azvoltagemap. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.