SLK file extension is used by Microsoft Excel. SLK is a SYLK (Symbolic Link) format file. Used for exchaning data between spreadsheets and other applications. SLK file contains all spreadsheet file data and some formulats and formatting settings; it doesn’t store merged cell data, text allignment settings, page breaks, or graphical objects.

Created SLK file will only contain only spreadsheet active during SLK file creation process. SLK files can be helpful in restoring corrupted spreadsheet files. SLK file stores data in text format.