Combine the cream cheese and all but 1/2 cup of the crabmeat in a medium bowl. Mix until thoroughly combined. Roll into an 8-inch log and refrigerate until firmed up slightly, about 1 hour. Refrigerate the remaining 1/2 cup crabmeat until serving.
Meanwhile, combine the ketchup, horseradish, lemon juice, salt and some pepper in a medium bowl. Taste and adjust to your liking.
Place the log on a serving platter. Spoon some of the sauce over it, reserving the remaining sauce in a small bowl to serve on the side. Sprinkle the reserved 1/2 cup crabmeat on top and garnish with the chives. Rub the garlic onto one side of each slice of bread and arrange the bread on the serving platter.