You can follow these steps to disable videos playing automatically in your Linkedin feed.
- On your Linkedin Feed, Click on ‘Me’ dropdown in menubar
- Go to Settings and Privacy
- Go to AutoPlay Videos in ‘Account’ tab ‘Basics’ secion
- toggle the switch and make it off.
ref. screenshot https://pbs.twimg.com/media/DSnZC7PUMAAWBOC.jpg