Results copied from SSMS splitting across columns when pasted into Excel
It is persisting 'text to columns' settings from earlier
Workaround:
Find an empty cell
put asdf
in that cell
Data|Text to columns
delimited
uncheck all the options
finish up
This problem can be caused by Excel "Text to column" feature. What it does is, it breaks a single column into multiple columns depending on which delimiter you choose. Once you use this feature, Excel somehow thinks it is still on and may affect your next copy and past operation.
To fix Go to Data > Text To column and select a different delimiter (other than space), such as comma or a tab. Then copy and paste. It should fix the problem.
Related weird question mark in Excel after copy and past