The title borrows a term from archaeology: grave goods are the objects buried with a person for use in the afterlife. Here the speaker imagines their own burial and makes a request that is both odd and tender. They want their out-of-tune kettle buried with them.
A kettle that is out of tune is one whose whistle has gone sour or wobbly. Instead of treasure or weapons, the speaker chooses a humble household thing, flawed and a little comic. The ordinary detail suggests a life lived at home, among small routines. The walk in the garden and the evening on ice give the opening a cold, still, slightly dreamy feel, as if death were a quiet extension of a day winding down.
The mood is wry but affectionate. The speaker doesn't sound afraid. They sound content with imperfection, even fond of it, and that fondness makes the request moving as well as funny.