Old crazed finishes are very fragile. You can reduce potential damage to these finishes with slick furniture polish or paste wax. But as you can see in the picture, liquid furniture polish (left) highlights the crazing and makes it look worse, while paste wax (right) adds a little shine and scratch resistance without highlighting the crazing.
So paste wax is the better furniture-care product for crazed surfaces. (There is a small area in the middle with nothing on it.)