I am sorry to hear that it takes a lot of time and might not load the results in Test Studio.
I assume that you are scheduling the test execution with a storage and scheduling server setup. If that is the case, all of the results are kept in the storage server and Test Studio tries to load them from there. It is currently not possible to reduce the number of results, without having to manually remove them 1 by 1 from the Results tab.
You can use an external tool to clear the results a bit, like the MongoDB Compass tool. This is the official tool for exploring and making changes to the MongoDB database that Test Studio uses. You can explore the options to delete all results that are generated a few days ago and keep the overall number of results low.
If this is not an option for you, or the issue persists, I will need your help to gather more details. Please clear/enable the application log and attach it zipped to your next reply, after you try to open the results. I will analyze it and try to advise you further.
Thank you for your understanding and cooperation.