Yes, you can resize the column widths on the Projects > Structure tab. To resize a column, hover over the edge of any column header in the second header row until the resize cursor appears, then click and drag to adjust the width. You can also show or hide columns from the More menu as needed.
Note that the group header labels in the top row (such as Project, Contract, Budget, Unbilled, AR, and Cost) will automatically adjust to match, as they span the columns beneath them.
Note: Not all grids in BQE CORE support column resizing. This behavior varies by screen.