I found this in several places but I cannot find the citation from Giertz.  I don’t believe it was in the “Hammer of God.

“Many Scandinavian Churches had a half circle communion rail. The half circle you see represents the church on earth called and gathered by the Spirit of God. Though you do not see it, the circle continues and is completed by those who have gone before so that here and now we anticipate the reunion promised, we see by faith what we wait to see with our eyes. The half-circle stops at the back of the chancel. Beyond the chancel, on the other side of the wall, would lie the cemetery, where the members of that parish would be buried. And that is the reason why the communion rail is only a half-circle. The great Swedish churchman Bo Giertz writes –
“Where the circle ends at the chancel wall, the fellowship still continues; in the churchyard is the resting place of the dead, the Lord’s faithful, who now are partakers of the great banquet in heaven. They are with us as a great cloud of
witnesses, they continue the small circle of people around the altar in my parish church, a circle that widens and is extended both back in time through the centuries and forward into the eternal world. It is a table fellowship without end. Shoulder by shoulder are they with us: our own faithful ancestors who once received the sacrament here at this altar, saints and martyrs elsewhere through the ages, and finally the Lord Himself and His apostles in the glorious kingdom in heaven above where the circle comes to its conclusion. This is ‘communio sanctorum,’ the communion of saints in Christ’s kingdom of grace. Celebrating the Lord’s Supper with my brothers and sisters in Christ, I am connected with the saints who sit at the Lord’s Table in the heavenly kingdom. I am counted as one of God’s holy people.”