Here is another way to insert blank cells without VBA
1. Copy data A1:B10 to bottom (A11:B20).
2. Format copied data in a unique way, say red letters.
3. Select both sets of data and sort. Red letters will be interleaved with black.
4. Go to Find and Replace.
5. At FindWhat:/Format/FormatFromCell, click any red letter cell.
6. Click Replace All.