Too many pending files

[Aristeidis]

So, when i first launched sourcetree there was a huge list of pending unstaged files from games to windows files. It is super laggy. I changed to ignored files and it is running just fine. I dont know what is going on since i am new to this. I can't seem to find the solution online. Is there anything i can do to fix this? Also why is it showing so many files? Thanks in advance!