I would prefer to work in a large company rather than a small one. A large company has more to offer in terms of advancement, training, and prestige.
In a large company, I can start at an entry-level position and work myself up to the top. I could start in the mailroom and, once I know the company, can apply for a managerial position. In a small company, there is not as much room to grow.
In a large company, there are a variety of jobs. I could work in sales, in marketing, in distribution, in shopping, or in any department I applied for. I could be trained in a variety of positions and would have valuable experience. In a small company, there would not be the same opportunity.
In a large company, there would be more prestige. I could brag to my friends that I worked for one of the biggest companies in the world. I would always have something to talk about when I met strangers. If I worked in a small company, I would always have to explain what the company did.
Working for a small company would not give me the same opportunities for advancement or on-the-job training as working for a larger company would. Nor would I be as proud to work for a small company---unless the small company was my own.