What exactly are you trying to do?
Merge cells is only useful for creating titles to go across multiple rows or
columns. Simply do what you were doing: Enter some text in the upper left
cell, then highlight this cell and the EMPTY cells you want included in the
merge, and click Merge Cells. Then, format the data as you like (I like to
center it and increase the font)
However, if you have a column of data that you want to join into one cell,
than this is a totally different process which depends on your data type.
If your data is numerical, type:
=SUM(C1:C10)
in the cell where you want to add up your data (C1 and C10 are the starting
and ending cells, respectively)
This will add up your column
If your data is text, type:
=CONCATENATE(F1,F2,F3)
in the cell where you want to join your data (F1, F2, and F3) are the cells
where your text originally appears. Use ," " to insert spaces.