yes
<table>
<tr style="border: 1px solid #000000">
<td>something</td>
<td>something</td>
<td>something</td>
</tr>
<tr>
<td>something</td>
<td>something</td>
<td>something</td>
</tr>
<tr class="border-black">
<td>something</td>
<td>something</td>
<td>something</td>
</tr>
</table>
tr.border-black {
border: 3px solid #00000;
}
you can have inline like I did with the first row or you can have a class like I did with the third row. the possibilities are endless... but you can assign borders 3 ways.
external style sheet - if its going to be used in multiple tables
embedded style sheet - if the style is only going to be used on this page
inline style sheet - style is only used on this element