Originally Posted by Guessed

There is no built-in option in Word to highlight duplicate 'words'. There is in Excel but you already discounted that suggestion earlier.

It appears that you are not actually looking for duplicate words but appear to be looking for duplicate cell contents.

We probably need to assume that you don't need to find multiple dose sizes (as alluded to by the contents of the first row) and that the first column of numbers is manually entered rather than being autonumbers, then a macro based on the following principles would do the job.

1. Sort the table based on column 2
2. Query the cell contents in column 2 and highlight the cells where the cell contents match the cell above.
3. Re-sort the table based on column 1 to get the table back in the original order