JPEG into BlobFields

Hy, my Name is Mike, and I'm from Germany, where we can see the Spring.

First I have to say, I have read all Items in this Forum
about JPEG.
Some part's are not quit sure for me.
I work with D4 Prof.

First a simple Question:
-I have now 750 Pictures in my Blob File (mb).
-I use Paradox7 and the Filesize now is about 17MB.
-I expect finaly to have 3000 Pictures.
-Then the Filesize will be about 68MB!
-What is the Limit (MB) of the >mb< File?

My next Question:
What I like to do:
-I like to save JPG's to a BlobField in my Table.

Right now, i havea JPG previewing in a Image1.
Then I Assign it to a Bitmap.

After some Sizemanipulation, I copy it to a other Bitmap.
(Because I like to have a fixed size with a ratio)

Then I save my Bitmap to a MemoryStream.

After that I write it into my BlobField

-As I'am not so perfect with Delphi, I ask my self if this
 way is Ok for some Expert's too.

Here comes my next doubt's.

Mr. Razvan Fechete wrote A Code Like this at the Forum.
I don't understand why he use a TJPegImage??
As I understand the BlobField cannot have a JPG Image.

If the Blob Field can have a JPG inside, then how can i get
a JPG with TBlobStream inside the BlobField?

Sample read routine from Blob:
  JPegStream: TBLOBStream;
  JPegImage: TJPEGImage;
  JPegImage := TJPEgImage.Create;