Active Rental Car

It is written (partly) in English, I am assuming? Look under IMPORTANT INFORMATION and then click on driver to read this information:-

A full license held for minimum of 2 years with no major endorsements. UK license holders need to present the photocard. If your driver's licence is not in the Roman alphabet (i.e. if it is in Arabic, Greek, Russian or Chinese) you are required to bring an International Driving Permit and your domestic licence. For driving licences from countries not part of the international driving licence treaty, an official translation of the licence must be presented with the original licence. When renting within the EU, customers from non-EU countries must also present an International Driving Permit along with their domestic licence.

IDL is a translation, reading the information officially you need an IDL. But I think you will be okay, with your Indian one as it is in English anyway.

Malta is a little strange as the section you have just read, is generic as Malta as you know is English speaking. I dont see a problem so go ahead and book.