"Restaurant" means any public place kept, used, maintained, advertised and held out to the public as a place where meals are served, and where meals actually are served and regularly served, without sleeping accommodations, such space being provided with adequate and sanitary kitchen and dining equipment and capacity and having employed therein a sufficient number and kind of employees to prepare, cook and serve suitable food for its guests, and where the sale or consumption of alcoholic liquors is only incidental to the serving of meals. The fact that fifty percent or more of the gross revenue in any month from the operation of the licensed premises is derived from activities other than the serving of meals shall be prima facie evidence that such business is not a restaurant within the meaning of this chapter. (Ord. 7-1974 § l (part), 1974)