It depends on the mayonnaise and your dietary restrictions. Mayonnaise that does not have any sugar, vegetable oils, additives, and/or preservatives can be part of a healthy diet when consumed in moderation. This also goes for any dairy-free cream substitutes like coconut cream.  If you are concerned about the ingredients in coleslaw from the store you can opt to make your own and control the ingredients. It is important to note that portion size will also affect the health of this food no matter if you bought it at the store or made it yourself.  Coleslaw can be part of a healthy diet since the bulk of its ingredients are vegetables which are recommended as part of a healthy diet. The overall healthiness of coleslaw with mayonnaise or another non-dairy cream depends on its specific ingredients, how it is prepared, and what else you are eating.