Your winding key should look similar to this one
If you can get help, two people are much better than one for this job. Find the winding key and have a person standing at each end of the table ready to very slightly lift the table when you begin winding to take the pressure off the castors (wheels on the bottom of the legs) winding mechanism and table legs. Gently wind out the table and keep winding until you feel you have opened up enough space to fit the number of leaves you wish to use plus a little bit of extra space.
As you wind the table closed, stop about 2cm before the gap is closed and get your assistant to guide the dowels into the location holes as you gentle wind. With old tables this is a delicate process to prevent the dowels damaging the edge of the table or leaf.
As the table closes take care not to nip your fingers or over tighten the dining table (it should be closed just enough to keep the leaves firmly together).
If the table is an earlier model and just pulls open and pushes closed do be even more careful not to damage yourself or the table. Also, if you have a pull out table you'll need to remove the brass table clips at each joint before attempting to pull it open and then secure the leaves in place with the clips once the table is extended.
At the end of the Festive period when the table leaves are taken out just reverse the process and again be careful as you close the table together to line all the dowels up with their location holes .
May your Christmas be Merry & the New Year prosperous!
Graham Smith Antiques