June 8 (Reuters) - Canada’s main stock opened higher on Tuesday, a day after hitting record high, as data showing a surprise domestic trade surplus in April lifted sentiment. * At 9:31 a.m. ET (1331 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was up 20.9 points, or 0.1%, at 20,056.2. Reporting by Amal S in Bengaluru; Editing by Amy Caren Daniel Our Standards: The Thomson Reuters Trust Principles.