The tip is for service. There are 4 areas of service provided by staff:
1) Answering my menu questions, taking my order and unrequested/requested suggestions
2) Bringing the food/drink to the table and making sure everything is correct (including condiments, etc)
3) Providing refills as appropriate and checking that everything was OK (temperature, taste, etc)
4) Cleaning (bussing) the table.

I generally give 20% when the service is good in all 4 areas.

Based on the OP's description of the iPad menu, given that all other elements were there, I'd say 15%. If no refills/checking then another 5% gone. Same with bussing the table.

This would be the same where I order from the counter. That doesn't count as "service" unless its exceptional.

The problem, of course, is that the tip is given PRIOR to the service. In that case, no tip on CC but appropriate cash tip left in a tip box, if any.