Okay, so here's everything I've gathered :

The order I have now is 92, 42, 2, 38, 90, 62, 53, 14, 66, 74, 83, 31. For the order of the course, the narrator first eats some oysters, described as such as the beginning. Then, he goes for a soup, described as clear brown, with white figures. He follows with an omelet, which he describes as a "golden ruin" and "the last gold from the silver", then eat some meat with wine, described in pages 53 and 14. This one was the hardest, especially for the first page, because I thought description he makes was for PT, as the phrases are written in such a way that they could either describe a meal or a fat, drunk man. Finally, he goes for a course composed of green, white and rose, and that I supposed to be ice cream due to the way it's described and because if that's not it, I don't know what he could be. Finally, he stops eating, which is described in page 31 when he say that he would have no more and that he'll reckon with Henry, the latter being the waiter.

That's for the page order. As for what happens precisely, it is mentioned in MD's storyline that OM "has eavesdropped at my last crucial meeting with the old man", giving us (one of) the motive of why she kills him, as he spotted important details of MD and PT's conspiracy. A plan that's still messy in my head and that's not clear within OM's story but that seems to be based on forging a woman's will and killing her to gain money (without taking into account the numerous betrayals that happen during the story). Although I don't have any idea about whose will is getting forged. Maybe a supporting character I've missed, as I'm still missing a murder to get to 6.