If Joseph has 14 comic books and Tessa has \( t \) times as many comic books as Joseph, you can express the number of comic books Tessa has with the following expression:
\[ \text{Number of comic books Tessa has} = t \times 14 \]
This can also be simplified to:
\[ 14t \]
So, Tessa has \( 14t \) comic books.