λόγος can refer to a "word," or a series of words (i.e., "statement"), or in a much larger sense to the matter to which the words refer. So what were the disciples not to talk about after Jesus' transfiguration?
If you translate word-for-word in Acts 6:2, you miscommunicate. The Apostles were not wanting to stop being waiters, they weren't asking to stop “waiting on tables.” They understand that their "service" is different." They understand that their "service" is different.