Kitchen Worktop Restoration

I have old wooden kitchen worktops. I was wanting to have a laminate surface on top so it's a smooth and easy wipe clean surface. At the moment liquids soak into the wood and some areas of the worktop have stained black and some of the surface has an annoying stickiness to it which I can't get rid of by using hot soapy water.

Any advice please? If not advised to try and put a laminate cover on top can I try sanding and putting on some kind of varnish to get a smooth clean surface again?...

Kitchen Worktop Restoration