For a small local feast, you can be pretty sure that everybody gets every dish. For larger events, it becomes much harder.
The “default” serving method is to call for servers, who then keep dropping off dishes to tables until everything is served. This works reasonably well if the intent is to serve exactly one dish of each type to each table. But people won’t notice if two dishes make it to one table, and then another table misses out.
If you use that method, you need to send somebody around after the service to ensure that everything has got everywhere.
When I was in Torlyon (SCA Yass), we had lots of 100+ person feasts. (Before streaming video and so many computer games!) We made decorative table runners in shire colours, each with a heraldic motif (crescent, fleur-de-lys, etc). When the course was announced, each person would send a couple of servers up and collect them from a sideboard, marked out with the same symbols.
That worked pretty well, but there were occasional issues where a dish limped out slightly later and people would whisk the dishes away as they were being set down.
Okewaite feasts tend to have about 60 people, and mostly we use the default method. Increasingly, we send out big platters of mixed foods, and it’s harder to lose a dish.