PDF catalogued as a schematic, though the name 27lc4096 reads like a component part number in the 27-series EPROM family, with LC usually marking a low-voltage CMOS version. No board, brand or device is given, so treat it as a chip datasheet of about 142 KB. Technicians use such sheets to check pinout, supply voltage and programming conditions before reading or writing the part in a universal programmer. Compare the full marking printed on the chip, including speed suffix, before relying on the figures.
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.