If you can do a bit of programming, you can do this
relatively easily using Find & Replace (and a loop or
Case statement to do the repetitious processing). I have
simplified the details, but basically you need to follow
the steps below.  
1. Work out what your table headings should be from the
open tags, e.g. <Name> becomes Name and <Age> becomes
Age. Build up the first row of the table with tab
separators, eg.,
Name^tAge^p   (^t is a tab, ^p is a paragraph marker)
2. Change the tags in the middle into a tab marker so it
looks like this:
<AdrBook><row>
Name^tAge^p
      <Name>Alex^t14</age>
   </row>

You can do that by searching for </name>*<age> and
replacing it with nothing, but the syntax is more
complicated than that (you have to stick / or \
characters [I can't remember which offhand] in front of
the special characters). Open up the Help file and learn
about how to do Find & Replace with Wildcards. You'll
need to practice this.

3. Then, delete all the other tags except for the two
<AdrBook> tag until it looks like this:
<AdrBook>
Name^t^Age^p
Alex^t14^p
Alex 2^t24^p
</AdrBook>

4. Select everything within the <AdrBook> tags and
convert Table to text using tabs.

5. Format the table and delete the <AdrBook> tags.