spanning a data cell w/o headers

Hi EEE:
Given an array of column name, array of column values and an array of comments, i would like
to display in an HTNL page in the following way:

-----------------------------------------------------
ColumnName1 | ColumnName2 | ColumnName3 | ColumnName4        
-----------------------------------------------------
columnvalue1a| columnValue2a|columnvalue3a | columnvalue4a
-----------------------------------------------------
      1. comment1a
        2. comment2a
-----------------------------------------------------
columnvalue1b| columnValue2b|columnvalue3b | columnvalue4b
-----------------------------------------------------
      1. comment1b
        2. comment2b

My implementation looks like
<table>
<tr><td>ColumnName1</td><td>ColumnName2</td><td>ColumnName3</td><td>ColumnName4</td>
<tr><td>ColumnValue1a</td><td>ColumnValue2a</td><td>ColumnValue3a</td><td>ColumnValue4a</td>
<tr><td><ol> <li>comment1a</li> <li>comment2a</li> </ol></td></tr>
 
So, far I am having difficulty in the following subsections
1. The third part shows the numbered list of comments but its width is restricted to the column1's width. How can I get it to span all the columns?

2. How can I set the width of the table to 2 rows and rest of the row wraps around, like so?

-----------------------------------------------------
ColumnName1 | ColumnName2 |
ColumnName3 | ColumnName4        
-----------------------------------------------------
columnvalue1a| columnValue2a|
columnvalue3a | columnvalue4a
-----------------------------------------------------