In my current project I use the table field as a kind of easier accessible replacement for the structure field, where every table column equals a single field in the structure field and every table row equals a single structure field entry.

In this scenario it would be super helpful, if the editors could only edit the table rows, but not the table columns/headers as editing, adding or changing headers/columns would actually break the expected data structure.

In the table blueprint a feature like this could be solved by a new columns-property that would accept an array of column names:

fields:
  table:
    type: table
    label: Table with predefined columns
    columns:
      - Column A
      - Column B
      - Column C

This setting would predefine the amount and header-titles of the columns, so no need to add additional column settings like maxColumns: 3 or minColumns: 3.

Regarding sorting, I would also love to have sortable rows but non-sortable columns in my use case, but it might be a more flexible solution if predefined columns wouldn't be automatically set to be non-sortable, but if the sorting property would simply become more flexible – this could be achieved by adding the following values to the sortable-property:

sortable: true (all)
sortable: rows
sortable: columns

I think with these additions the table field would become a lot more flexible and could be considered as a solution for quite some scenarios that can only be handled properly by the structure field (or subpages) at the moment.