Home insurance does not provide coverage for normal wear and tear on these items. If your patio table suffers a crack as a result of age, that will not have protection. It also does not apply if someone in your home causes the damage.
This might include a child hitting it, for example.
Rather, it applies in unexpected events including storms. It should provide financial protection for your patio furniture if it suffers damage due to lightning, fire or wind. If large hail hit the structure of your patio table shattering the glass, your coverage applies here, too.