PROBLEM: when I use “Format as Table” to format a range the “Merge and Center” button becomes inactive and I can no longer merge cells. Why?
SOLUTION: the Table format will stop the merging of cells. However there is a work-around.
The Format as Table command can be used to quickly apply a professional format to a selected range. However, in applying the format you are also applying the functionality that Tables offer. As a result you will no longer be able to merge cells. Read more