thanks for your question.
The problem here is that CSS code can not be used to find specific content. It can only match "meta" data that is associated to each element on a page.
Therefore, it is necessary to wrap the desired content (like "Trumpet") in an element that then can be styled with CSS code.
The solution to this is to indeed wrap the word in HTML code, and the Advanced editor can be used for that, indeed (although it doesn't directly offer a function for this).
You would basically have to wrap "Trumpet" like this:
similar to how it is explained in the question "How can I highlight certain cells or their content?" in the TablePress FAQ at http://tablepress.org/faq/
If you have very many occurances of this word, a more automatic solution could be considered. This would however involve programming of a custom Extension in PHP code, that uses the available filters in TablePress to manipulate and extend the data in the table, before it is printed on the page.