When a woman who has been sewing puts her thimble on the table as she sits down to eat, it is a sign that she will be left a widow if she marries.
Central Maine.

When a woman who has been sewing puts her thimble on the table as she sits down to eat, it is a sign that she will be left a widow if she marries.
Source: Current Superstitions (1896), entry 1223.
Fanny D. Bergen, editor.
Modern normalized navigation; the historical attribution above remains unchanged.