Although it's tough going, you canactually get something from this. First, be aware that the basic operator of BNF is the equivalence operator "::=" which means roughly "is identically the same as" and the vertical line character "|" is approximately the same as "or". So, you know from the above that there are just 11 valid types of VB.NET statements. Some, such as SyncLockStatement, are completely new to VB.NET and their use is an advanced topic. But LocalDeclarationStatement is just the DIM statement covered on the next page.
But, in case you want a language and syntax reference that is genuinely authoritative and detailed, Microsoft provides one at their site: Visual Basic .NET Language Specification.

