Very small 24.5 KB PDF titled r12864, giving little detail beyond the number. The 12864 figure usually indicates a 128x64 dot graphic LCD module, but the manufacturer and controller are not stated in the name and should be checked inside the document. Such sheets normally give the connector pinout, supply and contrast voltages, backlight ratings and outline dimensions. Use it to wire or test the module, and compare the pin order with the actual board, since 128x64 modules from different makers vary widely.
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 @acodis_lcd_datasheets_EDID. 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.