in a relational database, can we have a table without any relation with the other tables?

Question

in a relational database, can we have a table without any relation with the other tables?

Answer 1

Yes. The way relations are expressed are with foreign keys. If a table you generate has no Foreign keys, and no foreign keys in other tables point to this table, it has no relationships.

It can still be given a relationship later though so don't worry about shooting yourself in the foot.