It is understood he never recovered consciousness.
Four other guests were wounded in the incident on December 28 last year. Press reports at the time said the attacker’s blade was 18 inches (45 cm) long.
Grafton Thomas, a 37-year-old man from a nearby village, was charged in January with five counts of attempted murder. Police said he kept journals containing antisemitic content.
Officers said he had blood all over his clothing at the time of his arrest and smelled of bleach, and that he said “almost nothing” when they stopped him.
Mr Thomas has pleaded not guilty to the charges.