Definitions:

1. Refers to someone who shares a table with you, typically during a meal or at an event. NOUN
   • At the wedding, I had a pleasant conversation with my tablemate, who was also a friend of the bride.
2. Used to describe anyone sitting at the same table, often implying a casual or social interaction. NOUN
   • The tablemate beside me kept chattering during the lecture.

Synonyms:

• dining companion
• table companion