How do I insert a table from a Word document into an Exel worksheet.
Have you tried copy and paste? In my experience, Excel is usually pretty good at taking data from a Word table and properly parsing it in Excel. Use the Data->Text to columns command if needed to parse the data manually.
Or how do I construct such a table from scratch in Excel ?
Select the cell where you want to table to be located, and begin entering data in individual cells.
I would want the table to look pretty much like it does in a Word document, i.e. darkened borders...Also, how do I make the border of some columns in Excel darkened or in bold type, while making sure the border of other colums are not darkened.
Select the cells to format and click on Format->Selected Cells->Borders tab and select the desired borders format.
"separated" from the rest of info on the worksheet.
First thought would be to leave a few rows/columns between the other data on the sheet and the table. I will often build a table in its own worksheet within a workbook.

Hope that helps.