The .Net Header displays some information the .Net Header (if any) that is present in the PE file.
Framework version
The .Net Framework version
MetaData Version
The .Net Metadata version.
MetaData Flags
The .Net Metadata flags.
Size
Size of the .Net Header
Flags
CLR flags. As specified by .corflags directive in ILASM or /FLAGS with ILASM compiler.
.Net Entry Point RVA
The relative virtual address that defines the native entry point for this .Net application.
This is not displayed if a .Net Entry Point Token is defined.
.Net Entry Point Token
The .Net method token that identifies the startup function for this application.
This is not displayed if a .Net Entry Point RVA is defined.
MetaData
Relative virtual address (RVA) of the .Net Metadata inside the PE file.
Resources
Relative virtual address (RVA) of the managed resources inside the PE file.
StrongNameSignature
Relative virtual address (RVA) of the strong name signature for this PE file.
CodeManagerTable
Relative virtual address (RVA) of the Code Manager table.
VTableFixups
Relative virtual address (RVA) of the virtual fixup table.
ExportAddressTableJumps
Relative virtual address (RVA) of jump thunks.
ManagedNativeHeader
Relative virtual address (RVA) of the managed native header. Reserved for precompiled images.
For a more detailed explanation of the fields mentioned in this topic see Table 4-6, Chapter 4 of Expert .Net 2.0 Assembler by Serge Lidin.