Creates a table from {0} by applying the {1} operation to the rows. If the return type of the {1} function is specified, ...

Creates a table from {0} by applying the {1} operation to the rows.
    If the return type of the {1} function is specified, then the result will be a table with that row type.  In all other cases, the result of this function will be a list with an item type of the return type of the transform function.