Point #1: This is from the days when television sitcoms had "laugh tracks." That isn't real laughter. The audio engineer puts in the sounds of laughter after everything that is supposed to be a joke. In this case, I think the laughter is exaggerated.
Point #2: I agree with Chris Black. This is an unkind joke. The hostess is quite old. Although "Candy" isn't necessarily suggestive, it falls in a kind of cultural borderline range, like clothing that is a little too tight. It is "cute," slightly childish. It is a nickname that would usually be associated with younger women. Meanwhile, the actress looks, talks,, and acts "old." The incongruity is a little funny. But, despite the laugh track, don't think it was very funny, even in the 1980s.
An interview with the actress Candice Bergen, interviewed in 1994, said:
"Call her Bergen. Call her Bugsy. Just please, please don't call her Candy. 'I used to think, "What's it going to be like to turn 50 and be called Candy?" 'actress Candice Bergen says in the September issue of InStyle magazine. 'As I got older, people started calling me Candice because they must have thought it was more age-appropriate. I'm not crazy about either name.'"