people used these contests as solemn ceremonies to honor the dead?

Answer 1

Ummm you don't say "which" contests so it's hard to be clear.

But yes, humanity throughout the ages has some weird and wonderful ways to honor the dearly departed.

Answer 2

All the Greek Games -- the Olympian, Isthmian, Nemean and Pythian -- were said to have been founded as funeral games.

From Clement of Alexandria:
"Let us now proceed briefly to review the contests, and let us put an end to these solemn assemblages at tombs, the Isthmian, Nemean, Pythian, and, above all, the Olympian games. At Pytho worship is paid to the Pythian serpent, and the assembly held in honour of this snake is entitled Pythian. At the Isthmus the sea cast up a miserable carcass, and the Isthmian games are lamentations for Melicertes. At Nemea another, a child Archemorus, lies buried, and it is the celebrations held at the grave of this child that are called by the name Nemean. And Pisa, – mark it, ye Panhellenic peoples! – your Pisa is the tomb of a Phrygian charioteer, and the libations poured out for Pelops, which constitute the Olympian festivities, are appropriated by the Zeus of Pheidias. So it seems that contests, being held in honour of the dead, were of the nature of the mysteries, just as also the oracles were; and both have become public institutions."

Answer 3

Strictly from memory.....There were elaborate Gymkhanas as an Honor for dead Greek Leaders.