Here are a couple ways:
1) copy the table then open the Application Preview, then create a new document using the men item "File > New from Clipboard...",
Then use the rectangular selection tool to select the table , copy, then return to the email, paste.
2) make the table fit onto a printable page (using the Print View in Numbers), then print to a PDF and mail the PDF.... you can even use the email PDF directly from the print dialog:
What I see in the screenshot of the problematic email is a link that has a long "word" in it. It contains a bunch of words separated by underscores and you will notice the link only linebreaks when it gets to a dash, finally ending that long "word". In my testing, I got the same result when I used a link like that but not for other links. This makes the column extra wide and the result is the other columns get less wide (unless you increase the viewing width of your email which will let the other columns expand back out again).
I don't see a way to prevent this when doing a copy/paste of the table from Numbers. My suggestion is similar to one of Wayne's except this method and Wayne's kill the clickable links:
- Select the table in the Numbers sidebar
- Open the Preview App
- New from Clipboard
- Drag the image from Preview's sidebar and drop it in your email
You can also email the entire document as a PDF using Share/Email/PDF. If your document consists of only the one table this might work for you. It will preserve the clickable links.
I'm guessing this is a Mail problem, not a Numbers problem. It doesn't seem to handle the paste from the clipboard as we would expect it to. When you do the Numbers-to-Preview-to-Mail route, you'll notice it actually pastes a PDF image of the table, not a table "object" (or whatever you might call it) like it does straight from Numbers.