Combine ham, celery, pickle relish, mayonnaise, and horseradish; chill.
Spread 5 slices bread with ham mixture.
Top each with cheese slice, then 2 tomato slices; sprinkle with salt.
Cut remaining bread in half and place on top with slices "ajar" for peek-a-boo effect.
Toothpick pickle slice and stuffed green olive atop for garnish.