Hi Andrea
I can't see a standard block that looks like the one in your screenshot .
This looks like content from the report table block - showing a seminar report on the frontpage.
It doesn't sound like you have admin rights to edit the page so you may not be able to change this. yourself . There will be an edit cog if you are able to change the block.
You will need to find out who created the page and the report and try and get them to apply a filter for the block so that not so many events are shown.
regards