Discord is built with Electron, an open source framework that uses a modified version of Chrome to run the app. Discord could easily run up 2GB worth of RAM in your server. We would recommend running discord on your local machine to save RAM on the server.
Discord also shouldn't be ran on the server for your own security, although we trust our servers, we would like you to take as many steps as you can to secure your own belongings. Change the RDP port, don't login to your main email via chrome/browser and use the Discord app via browser but logout after each session.