"I misspoke," Goldberg said at the opening of Tuesday's show.
"My words upset so many people, which was never my intention," she said. "I understand why now and for that I am deeply, deeply grateful because the information I got was really helpful and helped me understand some different things."
She said that "words matter and mine are no exception. I regret my comments and, as I said, I stand corrected and I stand with the Jewish people as they know and y'all know, because I've always done that."
Greenblatt said that many people in the 21st century consider race to be simply about people of colour. But Nazi leader Adolf Hitler considered Jews to be an inferior race, which he used to justify the killings.
Goldberg's apology via Twitter on Monday night, where she said she was sorry for the hurt that she caused, was welcomed by Jewish leaders in the US, and the chairman of Israel's national Holocaust memorial invited her for an educational visit.
Goldberg's "apology and clarification are important", said Yad Vashem chairman Dani Dayan, who invited her to the World Holocaust Remembrance Centre in Jerusalem to "learn more about the causes, events and aftermath of the Holocaust". His statement said Goldberg's original comments indicated "a fundamental misunderstanding of the nature of the Holocaust andanti-Semitism".
During Monday's show, Goldberg had expressed surprise that some Tennessee school board members were uncomfortable about nudity in Maus.
"I mean, it's about the Holocaust, the killing of six million people, but that didn't bother you?" she said. "If you're going to do this, then let's be truthful about it. Because the Holocaust isn't about race. No, it's not about race."
She continued on that line despite pushback from some of her fellow panelists.