What is the Lord's Supper? It is God's presence. And, in God's presence there is both salvation and judgement. From Genesis to Revelation, we see humanity having intimate relationship with God, losing that intimate relationship due to sin and rebellion, Christ regaining that relationship through His atoning death on the cross, and the relationship being take to its joyful consummation in Christ's return in glory (the marriage supper of the Lamb).
What is the meaning of the Lord's Supper? Tracing the theme of the meal from Genesis to Revelation, we see that the meal is intimate relationship with God. When God is present, there is salvation and judgement. In the Lord's Supper, we see our judgement taken by Jesus in His broken body and blood poured out for us, and we see our salvation in God giving Himself to us in Christ represented by the bread and wine.