@Adexzy007, if you uploaded your CV and details to the Total website previously before now, then I want to believe the invitation is very authentic, Total doesn't not always advertise their scholarship to France, but rather select from those who are on their database and meet their criteria. I know people who have been invited before now, without any advert. However you can double check by confirming, I am believing that there are those who wrote the test last year, that are still in the house or at IFP, but still monitor this site.
As per the test format, I think it is aptitude test and probably skill test. I am not too sure, so I hope those with better information can confirm that for you.
All the best!