I have this form:

Markup is:
<table style="width: 100%; padding:5px;">
<col style="width: 20%; text-align: left" />
<col style="width: 80%; text-align: left" />
<tr>
<td>
<div>
Наименование</div>
</td>
<td>
<dx:ASPxButtonEdit ID="beWorkTypeName" runat="server" AutoPostBack="False">
<Buttons>
<dx:EditButton>
</dx:EditButton>
</Buttons>
</dx:ASPxButtonEdit>
</td>
</tr>
<tr>
<td>
<div>
Скважина</div>
</td>
<td>
<dx:ASPxButtonEdit ID="beWell" runat="server" AutoPostBack="False">
<Buttons>
<dx:EditButton>
</dx:EditButton>
</Buttons>
</dx:ASPxButtonEdit>
</td>
</tr>
<tr>
<td>
<div>
Дата начала</div>
</td>
<td>
<table>
<tr>
<td>
<dx:ASPxDateEdit ID="deBeginDate" runat="server">
</dx:ASPxDateEdit>
</td>
<td>
<dx:ASPxButton ID="btnDateChange" AutoPostBack="false" Enabled="false" Text="Изменить дату"
runat="server">
</dx:ASPxButton>
</td>
<td>
<dx:ASPxCheckBox ID="cbIsMainWorkType" Enabled="false" runat="server">
</dx:ASPxCheckBox>
</td>
<td>
<div>
Основной вид работ в заявке</div>
</td>
</tr>
</table>
</td>
</tr>
Question is:
How do I get rid of this awful indent of table inside another table?
Try to style your inner table as follows:
EDIT: You also might need to remove spacing from the table rows and cells: