To my knowledge this is not possible in tabulate.
A way to do get a summary table from tabulate to have wrapped headers is
1. Create the table in Tabulate
2. Click Red Triangle > Make into Data Table
This will create a JMP Table from the Tabulate report, where you are then able to resize the column width with wrapped headers.
Hope this helps! If not, please make a submission to the JMP Wishlist: https://community.jmp.com/t5/JMP-Wish-List/idb-p/jmp-wish-list