Table is too wide

Hi, new website updater at mtriathlon.org
Goal: to update new races, include race results, etc.

I posted some race information and put results data from the race in a table form (copied from word). The page looks good when I view it from wordpress. However, when I view the page in a new explorer window, the initial information is sized correctly, however, the table is pushed way down to the bottom of the page under the sponsor sidebar because it is too wide. I wouuld like to fit the table to the size of the center frame, so the nav bar is on the left and the sponsor frame on the right.
What have I tried: I have tried specifying column sizes; no column sizes; table width as a % and table width as a fixed pixel size. For each of these the table looks good in the wordpress viewer, however, when I open a new window, it still appears too wide and is pushed below the sidebars. Any help would be appreciated.