Arcades and amusement centers where more than 10% of the retail floor area is occupied by two or more of any one of the following, exclusively or in combination: pool table, pinball, electronic and/or amusement machines or devices of any kind. This prohibition includes but is not limited to machines and/or devices requiring electric current to be operable. Nothing herein shall be construed to bar the installation of the aforesaid games and amusements in a retail business establishment otherwise unrelated to the operation of the devices. However, in no case may the devices occupy more than 10% of the total retail floor area open to public access.