Assign real-world nations/languages to the races...
Ok, Gnomes definitely have the weird names going on, but
if we take a starting point of:
Dwarves = German
Elves = French
Humans = British
From there we can reference the sample names in the PHB.
Continuing the race = specific nation in Europe trend,
Halflings = Spanish
Gnomes = Italian (Take a look at the art for Gimble in 3.5)
Half-Elves = result of the Normans conquering England in 1066
Orcs, like many hostile humanoids, infest all areas, so Half-Orcs
may be found in significant numbers anywhere.
So, I'd give Gnomes long, Italian names. The Gnomish names people have suggested in this thread would simply be Common translations from Gnomish.
(Ooh. Scary thought. The Gnomish Mafia!)