table-from-column errors

[shriram]

It's unclear to me why table-from-columns cannot work with empty lists, for creating an empty table of the right shape that will be populated programmatically. The document does not indicate that this would not work. However, the code

[T.table-from-columns:
    {"a"; [list: ]},
    {"b"; [list: ]}
  ]

produces what is essentially an internal error: