The formats of the materials published on the web site of the Ministry of Finance of the Slovak Republic are in compliance with the Standards for Public Administration Information Systems.
Regarding above mentioned instructions, files containing tables, e.g. MS Excel applications are published in XML format (not in XLS format).
To open an XML file:
Save the XML file to your computer's disk.
Open a spreadsheet application (eg MS Excel).
Click 'Open File' in the menu and select 'All Files' at the bottom of the opened window on the line labeled 'Files Type.' This also includes an XML file in the file opening menu.
Click the file you want to open, and then click the "Open" button.
Once you've opened the file, you can save the file in the format used by the application (eg, XLS) and work with it as a regular xls file.