Copy pasting tables from Excel to Powerpoint

I am copying and pasting objects/charts from Excel into Powerpoint as linked objects, so that these can be updated in Powerpoint automatically. However, I am running into minor formatiing issues.

So I copy and paste in to Powerpoint, all is good. Then when I update the link, the size and format of the file goes a little crazy. Depending on the chart, it will shrink or grow. But I can live with the sizes changing, as I can always make a macros to fit, however, after updating, the gridlines go all thin and skinny. Is there any way to fix that? I have already tried to use bold or thicker gridlines on the linked excel spreadsheet, however, this does not seem to solve the problem. Any help would be apprecited.

Now I do not know if this should necessarily be an Excel issue or a Powerpoint issue, but any help or suggestions would be greatly appreciated.