The answer suggested; [theTableView reload] definitely works fine. If you update the table every view seconds, however, your users will going to hate you and down-vote your app. No question.
Try to capture the reloading data in a notification handler. In that handler, check if the updated data belongs somewhere between the currently visible cells, if so, update the currently visible view. If not, ignore the updated data (but do add it to your underlying model). If the user scrolls further, after your update, cellForIndexPath: is called and the updated data will be drawn automatically.
reload is quite heavy to do every view seconds, certainly with a lot of data. drawing might get screwed up or worse..