[Vuejs]-Creating a scope without defining a component

In general, this is the kind of complexity that calls for a component, but from your trouble with <slot> I’m seeing that your use case must be somewhat complex and there may be reasons why you want to avoid making a component for this.

To your original question, assuming you already have some id field to index your table cells, you can make hovered a dictionary and index it with the same field. Note that due to vue reactivity limitations of javascript you can’t use hovered[item.id] = 1 because it won’t react, so you have to use $set(hovered, item.id, 1):

data: function () { return {
  hovered: {}
}

<td @mouseenter="$set(hovered, item.id, 1)"
    @mouseleave="$set(hovered, item.id, 0)">
  <button v-show="hovered[item.id]">