Translation:The workers are selling things for the kitchen in the mall on Saturday.
Til can be translated as to or for depending on the context of the sentence.
And in English for can have different meanings. For example, sell things for the kitchen can be interpreted as both "selling things on behalf of the kitchen" and "selling kitchen items". In this sentence, the workers are selling items to be used in kitchens (rule of thumb: for = on behalf of, til = for [someone/something]). I know the wording isn't exactly the best in this sentence though/it's confusing.