Those placemats, from the Parenthood GP, are disappearing when the Sims put the dishes on them. The correct thing was not to disappear.
SAMPLE GIF:
(Take into account that the empty plates on the towels are actually a decoration.) When the Sims pick up a plate of real food, the decorating plates disappear to clear the space for dishes with real foods. The problem is that not only the dishes, as the towels and also the cutlery are disappearing).
Comments
You may like to post feedback on this AHQ EA thread
https://answers.ea.com/t5/Bug-Reports/OPEN-PH-Vanishing-Placemats/m-p/6702911#M60624
http://forums.thesims.com/en_US/discussion/817478/hello-come-and-introduce-yourself
http://tinyurl.com/OneRoomOneWeek
http://tinyurl.com/rosemow
My Showcase thread https://forums.thesims.com/en_US/discussion/948861/rosemow-s-rooms-showcase