You can use the option reset.
Option reset causes asdoc to make a new nested table, i.e. instead of appending to the existing nested table, option reset will start a new table in the existing file
See this example:
* load the auto data set
sysuse auto
*Make a nested table where the dependent variable is price and independent variables are mpg rep78
asdoc reg price mpg rep78, nest replace
* Add variable headroom and then nest with existing table
asdoc reg price mpg rep78 headroom, nest
* Add variable weight and then nest with existing table
asdoc reg price mpg rep78 headroom weight, nest
Add another table of regression in the same file
This time our dependent variable is displacement. Please note that we shall use the option reset, which will start a new regression table in the file.
asdoc reg displacement mpg rep78, nest reset asdoc reg displacement mpg rep78 headroom, nest asdoc reg displacement mpg rep78 headroom weight, nest
