It's never off the table

I watched an episode of 'Friends', and in a conversation, Rachel said to Ross: "With us, It's never off the table", for Ross. What does that mean?

When people negotiate, sitting at a table, they may put down a contract, or written offer, for each other to read, and agree or reject.  If the paper/contract/agreement is taken 'off the table' that means it is withdrawn.  Something that is never 'off the table' is an offer, a topic, an idea, an agreement that is always 'on the table' - it can always be negotiated.  The offer is always open