Assuming standard knockout. In the first round, if you have 775 players, you would be giving 249 players a bye in the first round, not one. This gives you a total of ten rounds.
However, if you're playing Swiss-pairings with a final top-8 knockout, you'd give one player a bye and still play 10 rounds, three of which will be seeded knockout, giving a much fairer qualification system. I'd go to 8 rounds of Swiss though, with a cut at 6 rounds, possibly playing the last two rounds and the knockout on day two.
The only problem is that if blue/white lock decks are in fashion, you're going to have to be very strict on the time-limit and you'd need one head-judge and something daft like a minimum of 12 floor judges, not assuming breaks. I'd be happy with one level three as head judge, 8 level twos and 16 level one judges and apprentices.
Oh, hang on, you said table tennis? Sorry, I thought you said Magic: The Gathering.