The 1931 Chess Olympiad at Prague had the dubious distinction of being the only Olympiad where every single player lost at least one game. 10 victories in 18 games, was the maximum strike rate. The USA represented by Kashdan, Marshall, Dake, Horowitz, and Steiner won walked away with the Gold medal and the Hamilton-Russell Cup for the first time. This event had 19 teams in fray and for the first time, the rule that player order must be submitted with entry was enforced.
Paul Keres is the highest scorer in Olympiad history with 13.5/14 at the 1952 Helsinki Olympiad. This amazing 96.43% scoring rate is an all-time record. Keres drew his first game against Nilsson of Sweden and won the rest. Incidentally, Keres won 4 straight board Gold Medals from 1954 to 1960 which is also an Olympiad record.
The most expensive Chess Olympiad ever was hosted by Dubai, the United Arab Emirates in 1986. The organizers offered $1 million for free airline tickets to teams reluctant to participate. The previous Olympiad at Lucerne boasted 91 teams but 108 teams participated in Dubai.