Whim wham is an unusual and somewhat obscure term, so it's not surprising that there aren't a ton of synonyms for it. However, there are a few words that come close in meaning. One option is "trifle," which refers to something that's trivial, unimportant, or not serious. Another option is "bauble," which suggests something small, decorative, and perhaps frivolous. "Knickknack" is another synonym that conveys the idea of a small, decorative item, but it's also often associated with clutter or useless objects. "Trinket" and "gewgaw" are similar words that describe small, ornamental objects, often with little practical value.