Unfortunately, this use of the word relation, while I agree correct, has fallen out of favour, I think because it is confusingly similar to relationship, and because table is used everywhere instead (except academia.)

I'm not sure I understand what you mean about pointers though. I'd agree that if you have literal memory pointers, then you have an object database or a graph/network database. But entries in a relation based on values of candidate keys of another relation (that is, foreign keys) fit exactly within the relational algebra (natural join).

I don't see how information hiding in OO is analogous to not calling a database relational.