One of the most boring jobs one can do in LATEX is to write a matrix or a tabular environment. One has to keep track of all the elements, ensure that the environment is well formed, and that all things are where they are supposed to be. Good indentation helps, but there is a simpler way: using Kile's menu. Other than the option, it contains and (used in math environments). You will then have a matrix-formed input form that you can easily fill in with your entries. The option will display a simpler menu to set up a tabbing environment. In all these environments, you can easily set the number of rows and columns, along with other specific options.