These students work at jobs ranging from waiting on tables at a restaurant to skilled employment related to their fields of study or interest.
这些学生从事（这样的）工作,包括从在饭店里伺候餐桌到与他们的学习研究领域或者他们的兴趣爱好相关的有技能的职业.
整个句子的主语是：These students
谓语是：work at
宾语是：jobs
剩余的ranging from...to ..是现在分词短语,修饰宾语jobs,说明工作的范围很广.