I'm surprised I haven't really delved into the topic of tables earlier. I know I've thought of the idea a couple of times over the past year, but usually in context with some other mechanism.
Love them or hate them, tables are a part of many games.
The random monster and treasure tables in many early RPGs.
The devilishly elaborate tables that refer you to other tables when engaging the combat sequence in Rolemaster.
Tables designed for rapid generation of cities, regions and worlds in a variety of Game Master guides.
The curious tables scattered through the sourcebooks of RIFTS and GURPS.
Even the "modern" indie games fascination with oracles, due in no small part to the game "In a Wicked Age", are really just a new form of random data table accessed through the draw of cards rather than the rolling of dice.
I used to love tables, because you could introduce all sorts of elements into a game at random times, or when specific triggers were met. My early games (written in my high school years of the late 1980's/early 90's) seem to have a table on every page now that I look back on them. But this was an era when "realism" was sought in a game, and the quickest way to get "realistic" descriptions was to create a few cool effects then determine the likelihood of them happening and array them into a table of some sort.
Then I went through a phase where I hated them. They epitomised a lack of imagination and a constraint on the ability to tell a good story.
I've verged back to the concept of tables, as long as they are used sparingly and used with a specific purpose.
Like most mechanisms, if tables are used well they can really enhance a game, but if used poorly they just become dry collections of data stored in a randomly accessible format.
Good uses for tables include the ability to inject some thematic detail into an otherwise dry system. Good descriptors can help to provide an effective way of grounding a system into the "reality" of the game world. They can also be used to streamline certain effects, by offering a quick die roll that can then be referenced once for an immediate outcome (as long as they don't simply refer you to other tables....which might be good during character generation or story development, but can be incredibly frustrating in a high tension moment like combat).
Many of the features once found in tables are now handled behind the scenes in many computer roleplaying games, crunching numbers and generating outcomes based on random events are a forte of computers, so it makes sense to handle these things out of a player's sight. This is probably one of the many reasons why tables have gone out of fashion in many of the current crop of games.
...it's probably also a reason why tables often feature so heavily in the genre of game called the "heartbreaker", a longing to return to the old days of roleplaying before computer games became so prominent.