Repairing a varnished finish without refinishing entire piece

Hi all. I have an area of a coffee table edge that I need to repair and refinish. It's basically a small crack that has appeared. It is finished in a stain and varnish product that is oil based. I'm curious, is there a way of only applying the finish to the repaired area without it being too obvious. I am not sure I have enough varnish to refinish the entire table and thought I would ask before I go and buy another tin. TIA.

How long since the original finish? I would think that if it has been a year or more it will have faded somewhat so even the original finish will not match.
So unless you have a great eye and a range of stains to mix to match i wouldn't be hopeful.
But thats just my perspective.