I'd expect the gaps, because the gaps are a natural consequence of the structure being interesting - that clear patterns appear as soon as you assemble a bit of data.

Most spoofs of the PT are bad because they don't have any periodicity, wholly missing the point.

I suspect this happens because the PT is the most famous organized list in science, and it's structure (not a simple array!) is fascinating even to people who don't bother to understand what the structure means (logically, not to mention chemically).

If you are really into the "Periodic" and "Table" aspects, check out Theo Gray's Periodic Periodic Table Table posts ;-)