The life table sometimes called the mortality table is one of the oldest mathematical models in demography. In demography and actuarial sciences, life tables are essential tools for data analysis and predictions. The life table is a stationary population model where the total births and deaths are identical, and the total population of a life table is constant. The life table is perhaps the oldest tool to compute the expectation of life of a cohort of births. It is unclear if understanding human behavior, society, and culture were part of the human evolution. It is still unclear if there was a method for estimating longevity of humans prior to the life table techniques. In this chapter, we will learn the methodologies of the computation of life table and the assumptions involved in constructing various columns of the life table. We use the standard notations to represent various columns of a life table.