We have a Tabcin Tin / medicine tin with a slide top.  It contained 12 tablets and was produced by Miles Laboratories, Inc. Elkhart Indiana.  It measures about 1 1/2" x 2" x about 1/4" in h.  It shows some light to moderate wear - please see photo's.  The top slides to the side, functions fine.

Tabcin Tin Miles Laboratories Slide Top Vintage