The file is a compressed archive that likely contains documents related to economics, as the Hungarian title translates to "Wonderland of Economic Subjects."
Be aware that some browsers (like Safari) may incorrectly try to display the raw code of a .7z file as plain text, which will look like unreadable gibberish.
You can use 7-Zip on any computer, including a computer in a commercial organization. You don't need to register or pay for 7-Zip. How to open 7z files - Trend Micro Help Center
Only open this archive if you received it from a trusted source . Like any compressed folder, .7z files can potentially hide malicious software.
You may need an app like Unzip One or a similar archive manager from your device's app store to unpack the data.