E/B Piano Chord
E/B is a E Major chord played over a B bass note. Because B is the 5th of E Major, E/B is simply E Major in 2nd inversion, the same notes with the 5th moved to the bottom.
The dark key is the bass note (B); the coloured keys are the E Major chord tones.
Notes in E/B
Low to high: B (bass) , then E – G♯ – B.
How to play E/B
Play the bass note B low in your left hand, and the E Major chord (E – G♯ – B) in your right. Because it's an inversion, the bass is already one of the chord tones: you're just voicing E Major with its 5th on the bottom.