I want to create a fragment file that will only contain a CustomTable in the file. This is easy enough, but I do not know how to link/include it back into the main product.wxs file.
The fragment file is in the same project as the product file, and I have also tried adding an include tag for the file without success, and even putting the custom table into a WiX include file.
Is there a way to do this? Or is it going to have to live in the product file?
The WiX toolset compiles and links in a similar manner to the C/C++ compiler. The linker starts at the "main" entry point (Product element, in your case) then follows the references from there, which in turn follows references from there until all are resolved.
Part of your question is missing but based on the title I'm going to guess that you want a CustomTable element. Typically that CustomTable is processed by a CustomAction. There are a couple good ways to reference a CustomAction.
I would not use an include file.
You could try using EnsureTable if you'd like to make sure the table is created whether or not there is data in it. If you'd like to separate the custom table's schema definition from the data I believe you can just define them in separate fragments and reference the schema definition from the data definition fragment by opening with <CustomTable Id="your table name"> and defining the rows of data within it.
In general Wix won't pull fragments into the main authoring unless they contain elements that are referred to somewhere and since there is currently no such thing as CustomTableRef you may opt to use other elements such as an empty PayloadGroup or ComponentGroup that you can refer to (using a PayloadGroupRef or ComponentGroupRef respectively) from your main Bundle, Product or Module element as the case may be.
