E is commonly used as a response to something you don't have a proper response for, it is also commonly used in 'dank' or 'deep fried' memes. Apparently the meme is associated with Lord Farquaad (the main antagonist of the popular film Shrek) and due to the absolute chaos that is meme culture a YTP artist decided to make a video titled "Shrek but only when Lord Farquaad says E" The letter was a meme before this but the video brought it back into meme culture.
Guy 1:"Im super excited for the next episode of Waanda Vision"
Guy 2: "e"
Saying โeโ is a way of being confused, or not knowing what to say.
A - yo she gave me a fucking boner!
B - e?