Salt has long been a sign of hospitality and preservation, so a salt shaker is read as adding flavour, sharpness or truth to a situation. Passing it is traditionally taken as a gesture of fellowship.
Does the traditional reading fit your dream, or did it mean something else to you?
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.