What can we call those ladies?

Solution 1:

I've always referred to them as "ladies who lunch." According to Wikipedia the phrase means:

"Ladies who lunch is a phrase often used to describe well-off, well-dressed women who meet for social luncheons, usually during the working week. Typically, the women involved are married and non-working. Normally the lunch is in a high-class restaurant, but could also take place in a department store during a shopping trip. Sometimes the lunch takes place under the pretext of raising money for charity."

"The phrase "ladies who lunch" was introduced in the January 19, 1970 issue of New York magazine by the writer Merle Rubine,1 "Anyone with a fair figure, ready cash, fashion savvy and a safecracker's nerve can buy the best that Fifth Avenue has to offer on Seventh Avenue at half the price. The girls at Condé Nast and Harper's Bazaar have known this for years. Likewise the ladies who lunch at Restaurant X, although they'd rather be banished from the banquette than admit they got their Beenes and Blasses on a bargain basis."

Solution 2:

Socialites: someone who participates in social activities and spends a significant amount of time entertaining and being entertained at fashionable events attended by others of similar standing.