If you had told us where in this world the dining table was located, it might have helped. But it looks like a larva of a dust-lion (a relative of ant-lions) that lives in really dirty homes in the tropics.
Looks like it might be an antlion larvae, which can be found in the south of England.
The Suffolk Sandlings, Dunwich, Minsmere are known sites, and I think maybe Orford Ness.
Have you been to somwhere dry and sandy recently?