A garden party is read as relaxed, open-air sociability and pleasure in good weather. Dream books link it to ease, light conversation and the wish for a carefree afternoon among friends.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.