Having put myself through school in waiter/bartender occupations (for too may years), I have seen a myriad of tipping situations...from ZERO where I got "slammed" and was "in the weeds" and therefore did not give good service. These situations happen and it is just part of the job. To others, where I received 200% of the total tab (not usual I admit).

In the OP's situation, I don't think the waitress would have given a second though to whether she received $4, $10, or a $14 tip. She would have thrown it in her pocket (or tip jar) and went on with serving her other tables. As a waiter I did not sit and think about every tip I got and calculated the percentages. I knew if it was around 15% that was fine by me and I went on w/ my shift.

I also don't think that you "occupying" a 4-top in the restaurant/lounge when there was no other choice justifies adding another $10 to the tip as a gesture of saying "sorry" for occupying the table during lunch. Doesn't make sense....

What if I have a 4-top for lunch and they all order the soup of the day and that's all! Bill is low, so what? Do they add something more on (other than the usual 15%) because they feel bad for the waiter/waitress that they didnt order the steak sandwiches at a higher price?

just my 2 pennies.