I don't have a specific code sample. However, there are two approaches that I can think of. One is that you simply save the contents of the table using VBA code to disk, and then start up JMP and issue an Open command to return a Document object.
The second option is to open JMP, and individually retrieve the cell values from Excel and put them into a JMP data table that you have created using NewDataTable.
In both cases, you still need a trigger. The button serves as this with the UI. When do you want to save out the Excel information? One option is to do it when the worksheet itself loads. The other is when a cell changes. In both cases, the Excel VBA supports triggers that tell you when these events happen.