Indesign editing table lines

[Danny29443666ie4h]

Hi,

For my work I have to edit a document in Indesign. In the document there is a table. My predecessor probably made it once. I want to extend the light grey lines. I can't figure out what kind of lines these are and how the layout is made exactly. I can't find where I can edit these. Any idea? Thank you in advance.

Yours sincerely,

Danny

[pixxxelschubser]

Please press [Ctrl]+[H]      (show Frame border or similar)

and [Alt]+[Ctrl]+[i]      (show hidden characters)

and [Ctrl]+[Y]      (edit in text mode)
and show us a new screenshot. Or upload an example Indd without confidential data on a hoster of your choice and link here.

[Danny29443666ie4h]

 
As you can see, I use tabs for typing the numbers in the table. I just need to extend the horizontal thin light grey lines between the numbers.