There are a few quick ways to insert or delete rows and columns in Excel:

Inserting Rows:

* Right-click method:
1. Click on any cell within the row below where you want to insert a new row.
2. Right-click and select "Insert" from the context menu.
3. Choose "Entire Row" to insert a blank row above the selected cell.

* Home tab method:
1. Select any cell within the row below where you want to insert a new row.
2. Go to the "Home" tab on the ribbon.
3. In the "Cells" group, click the "Insert" dropdown arrow.
4. Choose "Insert Sheet Rows" to insert a blank row above the selected cell.

Deleting Rows:

* Right-click method:
1. Click on any cell within the row you want to delete.
2. Right-click and select "Delete" from the context menu.
3. Choose "Entire Row" to remove the selected row.

* Home tab method:
1. Click on any cell within the row you want to delete.
2. Go to the "Home" tab on the ribbon.
3. In the "Cells" group, click the "Delete" dropdown arrow.
4. Choose "Delete Sheet Rows" to remove the selected row.


Inserting Columns:

* Right-click method:
1. Click on any cell within the column to the right of where you want to insert a new column.
2. Right-click and select "Insert" from the context menu.
3. Choose "Entire Column" to insert a blank column to the left of the selected cell.

* Home tab method:
1. Click on any cell within the column to the right of where you want to insert a new column.
2. Go to the "Home" tab on the ribbon.
3. In the "Cells" group, click the "Insert" dropdown arrow.
4. Choose "Insert Sheet Columns" to insert a blank column to the left of the selected cell.

Deleting Columns:

* Right-click method:
1. Click on any cell within the column you want to delete.
2. Right-click and select "Delete" from the context menu.
3. Choose "Entire Column" to remove the selected column.

* Home tab method:
1. Click on any cell within the column you want to delete.
2. Go to the "Home" tab on the ribbon.
3. In the "Cells" group, click the "Delete" dropdown arrow.
4. Choose "Delete Sheet Columns" to remove the selected column.

Remember: When you delete a row or column, any data contained within those cells will also be deleted. Make sure you have backups or don't need the information before deleting.