Are you using it outdoors? Cypress, especially old cypress, is one of the most naturally rot-resistant woods there is. You will want to protect it from water, and sun to the extent possible for a long life. A fresh coat of paint is probably the best way to do that short of getting it under cover.

Inside you really don't need to do anything if you don't want to.

Awesome! I have it in the house. Thank you for the information!

And for goodness sake use it because that's what gramps intended for it.

A good coat of buffed-out furniture wax is all it needs.

And when you use it for a dining table, wipe up spills promptly, use trivets, etc. Any wood is susceptible to staining and heat.