Using a bread knife, slice the top off the 10-inch round loaf so the bottom half is slightly thicker than the top.
Scoop out some of the soft interior from the bottom half to create a shallow cavity, leaving enough bread for structure.
Spread about 1/3 cup of the olive salad evenly over the bottom piece of bread.
Layer the provolone, ham, capicola, Genoa salami, and mortadella on top of the olive salad, arranging evenly to the edges.
Spread the remaining olive salad over the stacked meats and cheeses, and drizzle any oil from the olive salad on the underside of the top piece of bread.
Place the top piece of bread back on, press down gently, then wrap the entire sandwich tightly in plastic wrap.
Refrigerate the wrapped sandwich for at least 2 to 4 hours (or up to about 2 hours and 10 minutes as total time indicates) before unwrapping and slicing to serve.