OK, two common situations, one for Word and one for Excel.
Word
Select the paragraph associated with the text then right-click and select Paragraph...
In the Paragraph dialog window set the Spacing > Before:, After: and Line spacing: as you desire.
Click OK.
Excel
If you are selecting the cells in the rows, setting the size, then selecting the rows and trying to use the auto-size function, it probably is not returning the result you expect (the auto size is fitting to the largest text point size in the row).
Instead, select the rows, then set the text point size; the row height should auto-adjust.
Note: The row height needs to be larger than the text size to be readable, eg. 8-pt text needs 11 pt row height.
Regards,
GEWB