The specific operation is as follows:

1. Open the data table to be summarized, click any cell in the data table area, select Insert in the toolbar, and enter the PivotTable report.

2. When creating a table/range in the PivotTable, the whole table area is selected silently, and the new worksheet is selected at the position where the PivotTable is placed.

3. In the data list dialog box, select the line label according to your own needs. Here, select the date and specification, and select the total item by value. The fields in the following four boxes should be dragged into the boxes with the mouse. All you need to do is make a line label and a numerical value.

4. The number of calculations is the default value in the numerical option, not the required sum. Double-click the cell of the Total item and select Sum in the calculation type set of the Value field.

5. After completing the above operations, click on one of the date cells, right-click the grouping option, and select the month in the grouping dialog box. If it is inter-annual, you can also choose the year.

6. In this way, the monthly summary data table is completed, and the specific sales volume of each month is also classified by products. It's easy to get it done in one minute.

Excel is the quickest and most convenient method, and there is no need to use some special sales analysis software.