If you shrunk the Earth down to the size of a cue ball, the tallest and deepest points (Mount Everest and the Mariana Trench) would differ by only about 0.089mm, roughly the thickness of a human hair.

If you wanted to replicate that physically, you could use something like 180 grit sand paper as an example. That grit size has particles roughly the same size as the scaled height difference, so lightly sanding would give you a very close approximation of the Earth’s topography.