wood this thick no matter what you do, but wax filler sticks offer one of the best ways to conceal cracks. Regular wood filler almost always makes a mess on projects like this because it comes loose in time. Instead, apply a finish to your completed table without filling any of the cracks that might be present. Bring the table into your home and let it sit for one full heating season. This will probably be enough to allow any inevitable additional cracks to appear before the wood stabilizes fully. Only then should you fill the cracks with wax. Choose a colour that’s identical to your table top or slightly darker. Filler that’s lighter than the surrounding wood looks bad.