I'm Israeli, living in a city which is a suburb of Tel-Aviv. This means I spend most of my evenings in Tel-Aviv and know it pretty well, so I was interested in looking at it from a tourist's point of view.
It's true most waiters in TA (and in Israel enerally) don't get paid and are expected to live off tips (or the equivalent of minimum wage if they don't reach it by tipping), but it's also a known fact that Israelis do leave tips, by age ranges:
teenagers (before their army service, e.g. up to 18) usually don't tip much (unless they work as waiters themselves).
students and soldiers, even though being poor, know (or remember) what it's like working in restaurants, and will therefore leave even up to 20% if they liked the service, and the necessary 10% if you were mean.
'older' people will usually be generous, but this varies. I never was an 'older person' so I can't tell for sure.
and another thing - larger groups tend to leave more money behind if they know their math. why is that? every person pays for himself, and rounds the sum up to include the tip. those round-ups will usually result in a 5-10% addition to your tip.
for conclusion, working in restaurants is one of the more worthwhile jobs for travellers... go for it! :)
Some of the waitressing work I did in Tel Aviv ( especially the area of little cafes and restaurants towards the big hotels on the beach front) had little or no wages. You were expected to make your money on tips.
Tipping has been a hot topic in the forum recently and people are very divided over whether to tip or not.
The choice is yours of course, but please think when you are served your food and if the server is friendly, polite and helpful consider a tip. After all we were only the victims of greedy employers and over generous tippers. If you are anti-tipping perhaps you can "do your bit" by being aware of this problem and not patronising those establishments that practise it?
Just a thought :-)