Well, the good news is that if you have been given a title that is this vague and open, you can let your imagination run riot and take this wherever you want to go. Your response does not need to be factual, and so you can either think of a splendid offer that you made to somebody else or that somebody made to you, or you could make up your own situation involving a splendid offer. Consider the following example:
Being the only son of my parents meant that I was showered by the attention of my grandfather, my one living grandparent. When I turned 18, I was shocked when he made me a splendid offer, and told me that he wanted to pay for me to take a gap year before I went to college so that I could travel around Europe. "I want you to live a little and enjoy yourself before you settle down to more serious study," he told me. "You have worked so hard throughout school, and I think you should have the chance to visit Europe and do some travelling." I was overwhelmed by his generosity, and more importantly, the love that was behind it. I now look back on that thrilling and exciting 12 months as some of the most formative years of my life. A splendid offer indeed.
So, hopefully this will give you an idea of the kind of thing you can talk about. The most important thing is to let your imagination go wild. Your teacher will like to read something that is a bit different! Good luck!