SELECT DISTINCT T.TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES AS T
JOIN INFORMATION_SCHEMA.COLUMNS AS C ON C.TABLE_NAME = T.TABLE_NAME
WHERE C.COLUMN_NAME IN ( 'Start_Time' , 'End_Time', 'Record_Type', 'User_Action')

DECLARE @SQL VARCHAR(MAX)
SET @SQL = '';
;WITH AgentTables AS (
	SELECT DISTINCT T.TABLE_NAME
	FROM INFORMATION_SCHEMA.TABLES AS T
	JOIN INFORMATION_SCHEMA.COLUMNS AS C ON C.TABLE_NAME = T.TABLE_NAME
	WHERE C.COLUMN_NAME IN ( 'Start_Time' , 'End_Time', 'Record_Type', 'User_Action')
), NumberedTables AS (
	SELECT TABLE_NAME, ROW_NUMBER() OVER (ORDER BY TABLE_NAME) AS RowNum
	FROM AgentTables 
)	
SELECT @SQL = @SQL + ' SELECT ''' + TABLE_NAME +''' AS AgentName, [Start_Time], [End_Time], [Record_Type] FROM ' + TABLE_NAME +
CASE WHEN RowNum = (SELECT COUNT(*) FROM NumberedTables) THEN ''
ELSE ' UNION ALL '
END 
FROM NumberedTables
ORDER BY TABLE_NAME

-- PRINT @SQL;
EXEC (@SQL);