How to Store Text Reports in a Database
Okay, I think that I'm beginning to understand the nuance of your question.
Given that space efficiency is a high priority, I think that you can strike the varchar(max) option from your list. Since your minimum file size is 11K, nothing is going to fit on a single page. All the files will be stored as BLOBs. SQL Server won't compress that (aside from compressing the backup), so you're not going to save any space with that approach.
Next, I'm going to make the assumption that processing time can be traded for space efficiency. In that case, I would recommend that you compress the files yourself before storing them and decompress before displaying them. This goes for any solution you end up going with. You should end up with better compression than letting the file system handle it (which applies if you use a Filestream).
So I think that your question boils down to Filestream (and possibly FileTable) or VARBINARY(MAX). The standard answer provided by Microsoft is:

When to Use FILESTREAM
In SQL Server, BLOBs can be standard
varbinary(max) data that stores the data in tables, or FILESTREAM
varbinary(max) objects that store the data in the file system. The
size and use of the data determines whether you should use database
storage or file system storage. If the following conditions are true,
you should consider using FILESTREAM:

Objects that are being stored are, on average, larger than 1 MB.
Fast read access is important.
You are developing applications that use a middle tier for application logic.

For smaller objects, storing varbinary(max) BLOBs in the
database often provides better streaming performance.

I think that you will need to reassess your figures using compressed file sizes, and then make a decision based off of that.