To do what you are attempting with proc tabulate I believe you would need to create additional class variables with the desired label for Var_a and Var_b and display the variables to suppress the labels. The new variables would obviously need to be on a class statement and the table statement would need to be modified to something like
table var_a_labeltext='' * var_a=''
Or move to proc report
The 2025 SAS Hackathon Kicks Off on June 11!
Watch the live Hackathon Kickoff to get all the essential information about the SAS Hackathon—including how to join, how to participate, and expert tips for success.