SELECT
    tx.Description,
    bestMatch.Payee
FROM tblTxns tx
CROSS APPLY (
    SELECT TOP 1 py.Payee
    FROM vwPayeeNames py
    WHERE CHARINDEX(py.Payee, tx.Description) > 0
    ORDER BY LEN(py.Payee) DESC
) AS bestMatch
WHERE tx.Description LIKE 'Tesco%'