No, it's for real, you could be there - tickets are being sold for the event due to take place on December 3rd. And it won't take place in a replica hall in one of the Universal Studios in Orlando, or Japan - it's an actual set where the movie was filmed. We're not sure how they'd pull off the floating candles, but one can assume it'd involve invisible wires and flameless candles as opposed to the ones that tend to drip hot wax.
According to UPROXX, Warner Bros. acquired a converted airplane hanger in London's Leavesden Studios in order to film all eight Harry Potter movies, "and since 2012 has been using two of its soundstages and its backlot to house sets and props used in the film, arranged for visitors to tour."
Seemingly this is the first time the studio has decided to host an event of this kind on a real soundstage. Only downside is, the tickets are a bit on the pricy side; they're working out at about 300Euro, but that does include "a studio tour, butterbeer, and a wand." As for the two course meal on offer, you'll be feasting on ham hock and broad bean terrine with pea purée or turkey with cranberry sausage stuffing, roast potatoes, gravy, and brussel sprouts. (Vegetarians get veggie lasagna.)" Because nothing says Christmas like lasagna.
For those looking forward to dining at long benches, the hall is going to be arranged with round tables (so it'll be like a wedding). Also, as there's going to be booze, you must be over 18 to attend.
Lastly, don't worry, "costumes are encouraged."