Yeah, but new people tend to over anticipate..making a nusance of themselves...IMo for first time workers, stick with filling the needs..don't try to jump the gun till you get to know the signs.
A couple signs I wish my recent waitstaff knew:
1. moving the glass to the edge (or anything) means take it away. or refill it
2. closing the menu and putting it down means they are often ready to order
3. look at your table and at the customers everytime you are out, even if you were just there ignoring them is not good, usually right after the waitress leaves the kid spills their drink and we need napkins

. but if they are ignoring you on your way, (and you were just there) glance for stuff at the edge and be on your way.
4. speaking of napkins, for families with small kids...bring em! if we ask for 'some' we mean a LOT.
5. If you are a restaurant that normally doesn't have kids, write a quick caution list to glance at if one should ever appear (hot plates should not be set down in arms reach of a child in a highchair! niether should knives, or even forks for that matter, pass all food to mom or ask before putting it down...often the kids meal has to be cut up before handed over anyway...oh and lids on their cups a must!) Oh yeah and don't offer icecream outloud! though it is safe with my kids, it may start a tantrum with others, offer dessert or fancy grownup words. Praise kids behavior you are more likely to talk mom into giving them dessert (raising you ticket total..possibly raising the tip, don't do this if the kids were brats, you would rather have them out than in

.)
6. Know what you are serving! I can overlook it in the cheap chains, but if I go to a fancy place and am prepared to spend a fortune for dinner, I want my waiter to know what on earth I am reading, so I can be adventurous and try something new but not blind...same for wines, know what on earth they are, a couple in each price range is fine, you don't have to be a conisuer, just know what wine goes well with most meals..course don't insult me, fact is, I only like 'pink' wines, let me

.
7. speaking of drinks...if someone orders a smirnoff and coke, they may want it seperate...apparently good stuff doesn't get drowned in coke...(yes I screwed that one up...)
8. for regulars, try to remember anything and everything, like that dude always finishes his pop before you come back for the appetizer, bring a new one with you. Or that missus always asks for no ice..so if the assistant who brought the drink screws it up you can offer to go fix it. The regulars are where you can really use your brain to make excellent impression..but never make it so they can't change their mind