Few questions on the Silver Star

1. Are the sleepers/Baggage Car in the front or rear?
2.Is there just one cafe car and have you heard if they run short of food going to/from Tampa. Recommend bringing own food?
3. In sleeper, will the attendant get food for you. Would save time waiting in line!

Currently, and for the last few years, sleepers and baggage car have been on the rear of the Silver Star.
There is one cafe car.
When I travel on the Star, it is usually south of Orlando and I have not seen it run out of food.
If you are in a sleeper, you can request that your attendant get your food for you, but I have not experienced long lines. I enjoy eating in the cafe car, as opposed to my room. I find waiting in line an enjoyable "people watching" experience at times. I am extremely mobile and do not have any problems standing in line.
I am a very picky eater and always bring snacks with me (even when on the Silver Meteor, the train on which I travel most often).

I would recommend bringing snacks just in case. It's kind of like taking your umbrella to ensure it doesn't rain

I travel on the Star from WAS to WPB a couple times a year and have not had an issue running out of food. However, I do eat a big lunch in the station and grab a sandwich, chips etc for dinner in my room. Breakfast and lunch from the cafe car the next day haven't been an issue with food or lines. I don't have the SCA bring me food but am sure he would. Give him a gratuity.

During day before Thanksgiving, does the Silver Star carry additional sleepers and/or cafe?

No. The Silver Meteor carries an extra Sleeper throughout the week though.