Here are two time-savers you can use to enter data in Excel:
AutoFill Enter the months of the year, the days of the week, multiples of 2 or 3, or other data in a series. You type one or more entries, and then extend the series by dragging. Notice the next item in the series appears next to the bottom right corner of the dragged section. Once the dragging stops, the cells are filled with the next items in the series.
AutoComplete If the first few letters you type in a cell match an entry you've already made in that column, Excel will fill in the remaining characters for you. Just press ENTER when you see them added. This works for text or for text with numbers. It does not work for numbers only, for dates, or for times.
Everyone makes mistakes sometimes, and sometimes data that you entered correctly needs to be changed later on.
Sometimes the whole worksheet needs a change. Suppose you need to add another column of data, right in the middle of your worksheet.