RAR archive of 6.82 MB named A105FN, which is the model code of the Samsung Galaxy A10 European variant. The name does not describe the contents, which could be schematics, boardview, service documents or firmware files, so open it with 7-Zip or WinRAR and check. Repair material for this model helps trace power and charging circuits, follow display connector signals and locate test points on a dead board. Confirm that the model code and PCB revision on the phone match before relying on the files.
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 .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.