Only the number 29020 identifies this 605 KB PDF, catalogued as a schematic; the pattern most likely refers to a 2 Mbit 29-series parallel flash memory datasheet, though vendor and revision are not stated. A technician would rely on it for pin assignments, sector structure, device ID and the program or erase command sequence before handling the chip in a universal programmer. Match the full marking on the package to the document, and keep a verified backup of the original image before writing anything.
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 @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.