Td,th cannot set margin in table

First of all, what we need to know is that we can set the margin for table tables, not set padding, set padding for cell TD, and not set margin. So, we can't set the margin property on cell TD to adjust the distance between cells and cells, but we can use this method to achieve the same effect.
1) Set padding
As we have just said, we can set the Padding property on cell TD to adjust the spacing between cells
td{padding:5px 10px;}
2) Use the label
We can add a label to a cell TD and then set the margin property on the label
p{margin:5px 10px;}
3) Set border-spacing (ie not supported) on table tables
Let's start with a brief look at the Border-spacing property. Border-spacing:length; Sets the spacing between the sides of a cell TD in both landscape and portrait. When you specify a length value, this value is used for horizontal and vertical spacing, and when you specify two length values, the first one is used for horizontal spacing, and the second value is used for vertical spacing.
table{border-spacing:5px 10px;}

Td,th cannot set margin in table