Hi zoltan259,
Thank you for using the Apple Support Communities! We understand you'd like to know if you can connect an external monitor to your iPad. We can provide you with information.
Here is how you may be able to connect an external monitor to your iPad: Connect iPad to a TV, projector, or monitor with a cable - Apple Support, and the cable you would need: About Apple Digital AV Adapters for iPhone, iPad, and iPod touch - Apple Support
We're not finding any information on your second question, however, so you would just need to connect as specified in the above articles, and test it out. Or, you can try reaching out to your monitor manufacturer, Dell, for continued questions.
Best regards.