removing water sspot on oak table

Hi, I bought an oak dining table from next a few years back. The thing is the wood is unsealed and since then we have had kids and now the table is dirty no matter how much I try to clean it there is still dirt. Is there a way of sanding it and sealing it or will this destroy it totally. ...

I have a new white ring on my oak table, How do I get rid of it? Does anybody know?

I have just finished stripping my Oak Table of all the gunk and gook build up over the years. I have decided not to stain it, as I have discovered it has beautiful grain and color. My question is, what type of Polyurethane should I use to protect it? And how many coats should I apply?:)

I have an oak trestle table that has not been sealed. I soak it with lemon furniture oil because it is so dry. Should the oak be sealed or rubbed with a wax to keep it from drying out? Thanks for answering.

I have recently bought an untreated oak dining table and although I like the appearance of it I am concerned that I should treat it someway before use to avoid staining etc. Any advice? :confused: