This is the 636th most frequent Serbian word.
многим
"Многим" means "to many" or "for many" in English.
Here, 'многим' is in dative plural form, used to indicate the indirect object of the sentence referring to 'many people'.
Многим људима је потребан одмор након напорног дана.
Many people need rest after a hard day.
In this sentence, 'многим' is used again in dative plural to denote the people who found the ideas appealing.
Њене идеје су се свиделе многим присутнима.
Her ideas appealed to many attendees.
The word 'многим' is in dative plural, specifying the recipients of the help offered by the subject.