You can use asdoc for writing multiple regression tables to the same document. asdoc can be downloaded from SSC and can be used with almost all Stata commands. Here is a short blog post that shows how asdoc can be used with any Stata command. You can also watch several YouTube videos that show the use of asdoc
* Install asdoc
ssc install asdoc, replace
Please note that I am using the nest option of asdoc in the following example. There are two other options to report regression output, they are (1) detailed regressions, which is the default in asdoc (2) wide regressions, which can be invoked by using the option wide. You can see further details on these in the help file of asdoc
asdoc reg price headroom, nest save(Regression) replace
asdoc reg price headroom turn, nest save(Regression)* Please note that option append is optional in asdoc, without
* option replace, all additional output is appended to the file
* Now start a new table by using the option reset
asdoc reg mpg price headroom, nest save(Regression) reset
asdoc reg mpg price headroom turn, nest save(Regression)