Not a big deal.

Not many companies want to be involved in lawsuits. If you disclose some secrets of the company to other companies, there can be some issues, but in general not many people know these secrets. They put these terms just to be protective.

If you are in my field, almost every offer letter you receive will be like this. I am not at a level that knows many secrets. If you are, you need to consider these terms, but it seems that you do not really have many choices. It is not very wise to discuss this with them. But maybe you can ask whether these terms apply if it is them who terminate the agreement.