Performance of inner join query for certain condition
Run one query, make sure you have good indexes

Select Name2 
From Table2 Inner join Table1 on Table1.T1ITable2.T1Id
Where Table2.Type IN ('A', 'B', 'C') and Table1.Code='ABC'


A graphical query plan will show where you need indexes

A million rows isn't much and well within capability of SQL Server