Tables parameters do still work in an OO environment. I often call legacy FM from within classes.
If you are transferring huge quantities of data, the network load using IMPORT/EXPORT and a table type is considerably more than if you use TABLES. Certainly, with RFCs you used to get a warning that table types in IMPORT/EXPORT can cause problems, simultaneously with warnings not to use TABLES! I don't know if this is still the case.