The response (measurement) data must be stacked in one numeric column. You must also have a column that contains the treatment levels and a column that contains the block levels. Treatment and block levels can be numeric, text, or date/time data. If you wish to change the order in which text levels are processed, you can define your own order. See Ordering Text Categories. Calc > Make Patterned Data can be helpful in entering the level values of a factor.
You must have exactly one nonmissing observation per treatment-block combination. Minitab automatically omits rows with missing responses, treatment levels, or block levels from the calculations.