No, you can't simply put multiple projects in the same folder generated by B4J Packager.
However, you can manually organize a shared folder with a shared JRE and several .jar files, and then create your own scripts/installers.
Install a common JRE (or JDK) on the target machine.
Then, distribute only the .jar files for your different applications, without repeating the runtime.
Each application can be launched with a script that calls `java -jar MyAppli.jar`.
But be careful, all your applications must be compatible with the same version of Java.
If an application uses specific native libraries, you must include them in its folder (AppX/).
Alternatively, you can create a single installer (Inno Setup, NSIS, etc.) that copies this structure to the target machine.