When you shop for a new table for your dining room, it's a good idea to evaluate the different features that certain tables offer. One feature that you'll commonly come across is a table's ability to change size. Known as an "extendable dining room table," tables can extend in different ways — but the bottom line is that the table can either be small or large. When you buy an extendable dining room table, you'll be able to quickly change the size of this piece of furniture when it suits you.