If I create a new row in my .xls or .csv table, then the Read CSV operator will automatically read the new row. Of course at Read Excel, it is needed to set a huge imported cell range to read the new row.
But the read operators do not read the new columns. Neither Read Excel if one set a huge imported cell range. It does not work. There are the 'data set meta data information' at both read operators, and here needed to add the new columns. But to add a huge number of columns does not work, because if an added column does not exist in the table, then the read operators will throw a failure message.
So if one does not know the exact size of a table (the exact number of the columns), and the number of the columns can change by the time, it is necessary to use the Import Configuration Wizard if the number of the columns change or set the correct 'data set meta data information' manually.