[RbnJrg]

Originally Posted by DaveLessnau

...
and for cellpadding="5", cellspacing="5" style, I'd need styles changing table border-spacing=5px and td, th padding:5px.

Does that sound reasonable?

That's right. The css property for cellspacing is "border-spacing" and the property for cellpadding is "padding".
In epub2 is allowed to use for example:

<table cellpadding="5" cellspacing="5" border="1">
    <tbody>
      <tr>
        <td>Hi,</td>

        <td>how are you?</td>
      </tr>
    </tbody>
</table>

Under epub3, the above code will give you errors with epubcheck. So, to mimic under epub3 that table layout, you should employ:

<table class="padspace" border="1">
    <tbody>
      <tr>
        <td>Hi,</td>

        <td>how are you?</td>
      </tr>
    </tbody>
</table>

and in your .css stylesheet:

.padspace {
    border-spacing: 5px;
    border-collapse: separate;
}

.padspace td {
    padding: 5px;
}

Of course, in order that the property "border-spacing" will work, "border-collapse" must take the value "separate". With "border-collapse: collapse", the property "border-spacing" won't have any effect. And you also could use:

<table class="padspace">
    <tbody>
      <tr>
        <td>Hi,</td>

        <td>how are you?</td>
      </tr>
    </tbody>
</table>

and in your .css stylesheet:

.padspace {
    border: 3px solid black;
    border-spacing: 5px;
    border-collapse: separate;
}

.padspace td {
    border: 1px solid black;
    padding: 5px;
}

to have control over the borders.