In “old” web application it was pretty common that there has to be a paginator to navigate through the large data set. Instead of presenting tons of rows (bad UI!) a NEXT/PREV link was next to the table for getting more data. Almost every table “component” has that (e.g. displaytag, tons of 3rd party JSF libraries, Rails,…) these days.
With “Ajax” and “WEB 2.0” this pattern is not dead (e.g. see twitter, google, …), but a different pattern on handling larger data sets is getting more and more attention. The data is loaded when the user is scrolling down to the “end” of the table. As soon as the *visible* data is almost presented an eventhandler (on the scroller) is using Ajax to fetch new data, to be displayed once loaded.
Sure, both patterns are valid in different usecases and the “new” option is pretty cool enhancement to rich web UIs.