A new mode is added to the Split Worksheet dialog to split worksheet by various numbers of rows. See below,

For example, input 10 2(2 20) 30 int the Custom Rows edit box, then after splitting, the 1st sheet contains 10 rows, the 2nd and the 4th sheet contain 2 rows, the 3rd and the 5th sheet contains 20 rows, the 6th sheet contains 30 rows, and the rest will put to the 7th sheet.