Hello Shelly2 and welcome to this great informative forum.
Congrats on your new Pinehurst.
There have been several different table configurations used over the years.
One is that if there is a slit in the center of the table there may be straps underneath that hold the table together and must be unsnapped before extending it open.
Two is if there is a slit in the center the table may not open to be longer but one have will lift open for storage and does not extend.
And three there may be a section under the table that just pulls out and snaps up. Then to get that section back in you will have to pull it out a bit and lower it to go back in. It is spring loaded.
And since you are a new owner consider joining the Heartland Owners Club as well as checking out the rallies that are held around the country.
Georgia has an active chapter.
Take a look at the navigation bar above and click on the Owners Club and Events to learn more.
Peace
Dave