So there are no animations for sitting & eating.
Here’s a solution:
You can spot your character to be sitting down, and then make them do an eating animation, although they would be standing up, you’d move them down to the height they were when sitting down.
You can use the camera to zoom in to not show their legs, if they are talking.
However, if someone else is talking, then unless there was an overlay covering their legs from showing, there isn’t really a solution.
You can always support a thread that requests this animation to be put into Episode Portal: