There are three primary reasons that a cat might be a mealtime slob. A little experimentation can determine which reasons might contribute to the situation and offer possible solutions.
Any person who has ever had a toothache can understand the discomfort of trying to eat. Even if your cat eats only dry food, she still requires professional tooth cleaning periodically. Like humans, some cats are more prone to dental problems than others. This might be attributed to malocclusions (crooked teeth or incorrect bites) or to various chemical components of the cat's saliva that lead to the inevitable tartar build-up and bacterial invasion. And don't forget the progression of time and its effect on the teeth and gums of aging cats. In order to promote tooth and gum health, schedule routine trips to your veterinarian for a dental check-up and tooth cleaning.
Badly Shaped Food
Cat food companies spend millions of research-and-development dollars to determine the optimal size and shape of kibble, so it only makes sense that some are more successful in this regard than others. The external coating of the kibble can also make a difference as to whether your cat's tongue can adhere to it enough to help transfer it from bowl to mouth. If your cat appears to have a problem either picking up or chewing the individual pieces of kibble, perhaps a change in brand of food would help, with the idea of going to a brand with an entirely different shape.
Canned or "wet" food is generally easier for a cat to transfer to her mouth, by using both the tongue and teeth. While shape is not usually the issue, although some canned foods come in shapes to be marketed as "stew" or "sliced," the texture can be problematic. Again, a change in brand can help you to determine if this is the source of the problem.
Note: When changing a cat's brand of food, always do so gradually, over several days, so that an upset stomach does not result.
The Cat's Nature
Sometimes it's just your cat's nature as a predator that causes sloppy eating. If you have ever seen a cat in the wild, perhaps on National Geographic or the Discovery Channel, you will know that large or small – panther or domestic cat – the cat might go to a great deal of trouble to capture and kill its prey, only to have it taken from her by larger, more aggressive predators or scavengers. The instinct to protect the food remains hard-wired in cat brains and can play a part in eating habits.
While that kibble or dish of gourmet canned food might not look very much like a gazelle or a mouse to you, your cat's instinct will be to grab a bite, then drag it away to a more private, protected place to eat it. This instinct can be even greater in cases of multiple pet households. The act of taking a bite and moving it can cause spillage both near and away from the food dish.