Why does putting new shoes on a table bring bad luck?

It is not just new shoes but any shoes. In mining communities the only time boots or shoes were placed on the table was when the family was informed of the death of a miner. His boots would be placed on the table to show he was dead. After that placing shoes or boots on the table was seen as either tempting fate or in poor taste. Seeing someone's shoes on the table could severely frighten someone if they didn't know that the person was alive and well.