HTML tables don't work quite the same way as Excel tables, so you might not be able to get everything on the screen if you have more than 6 or 7 columns with fairly minimal data.
One of the big tricks is that cells won't wrap if you have long strings without spaces, for example a URL or long API name. The column will be as wide as the longest unwrappable string in that column.
You may also need to check the HTML code, to see if Excel has left any code that might be affecting the table layout.
Thanks for your response! What we have noticed is that if we take the table from Excel,and Paste it into Word...and then copy it from Word into Robohelp, it looks much better. Still, the table is far too wide, and will not edit, no matter what we try. I will go into the HTML and see if your solution works. I'll let you know. Thanks again!
Another thing to try if you haven't already is to right-click on the table and selecte AutoFit > AutoFit to Window and see if that helps.
Thanks for your response! I'll try that and post it up here if it works.