When you work as a server for a senior living facility does that mean you will serve them food all day?

It depends on whether you're serving in the facility's dining room or taking food to residents' rooms.  Senior facilities usually allow their residents two meals a day, and then the resident pays out of pocket if he/she wants an additional meal.  There will be three to choose from (breakfast/lunch/dinner).  Those taking meals in their meals have the same arrangement, but a server who delivers their meals might start delivering the trays earlier than the time the dining room opens.  The server leaves the trays in people's rooms, then goes back and picks up the trays.  Servers in the dining room serve the meals that are ordered (there is a menu to choose from), and then picks up the dishes and after everyone has left, the servers bus the tables and carry the dishes to the kitchen to be washed.  There are certain hours meals are served.  It doesn't last the entire day.

At the facility where my MIL was in her final years, the food servers took food to rooms, served in the communal dining room, helped patients eat if needed, bussed tables after the meal, retrieved lunch trays from room, and probably helped clean in the kitchen before prep began for the next meal.

More than once I marveled at the kindness and patience of a server urging a resident to try one bite, or have a sip of this, it's chocolate, when the patient clearly isn't interested yet needs to eat.

Speed posts one answer. At the facility my aunt was in servers only served the food. Either by taking it to their table in the dining hall or to their rooms. They would pick up or bus the tables. They didn’t have too much interaction with the residents. 

It would depend on what your boss says.

I'm pretty sure you would be taking their food to them all day, which sounds like a pretty easy job

Whoever is offering a job of this type will have all the fine details so it is to them you should go and ask.  It will depend on the size of the care home and how many residents there are, how many are employed for this work and on how many floors etc.  Only the employer knows these details.  If you get an interview just ask for fine details of exactly what will be expected of you and get it in writing.

You serve them at meal times, breakfast, lunch and dinner, we eat just like anyone else!

You serve food during mealtimes.