Compact PDF of about 91 KB covering the 93C46 serial EEPROM, the 1 Kbit member of the 93-series Microwire family; the _3 suffix appears to mark a document revision or variant and is not further explained. Matching the 93C56 and 93C66 sheets of the same naming, it probably comes from one vendor series. Technicians use it to identify pins, set the ORG option and check timing before reading or writing the chip, and should keep a copy of the original data before modifying it.
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.