Your lamp or lamps have nothing to do with your end tables. If you wanted for the people on the sofa to be able to read of have a softer lighting then you could have the lamps on end tables or placed upon other furniture in the room. End tables have ...
Let's see, I would think your chances are about ~~~~~ to 1 Blessed Be... )O(
Yes they will work if they fit the fixture.... They will only draw the 20 watts they need to operate, so No, you will not blow the 20W lamps.... Ensure however that the lamps you will be using are rated for 220 volt operation... I am guessing you are...