Does your bed have both a mattress and a box spring on it? Seems like the mattress should be higher to match the height of your headboard and footboard.

To answer your question on side tables...my first thought is to go big! But then again, your mattress seems too low for anything taller than what your have.

In my own home, my bed is tall, and to scale. My bedside tables are not matching. Under one window is a dining table (drop leafs down) made by my grandfather. On the other is an antique living room side table also with drop leafs (wings down). The heights are perfect for lamp reading and putting books, etc. down when ready for bed.

Here is an example: ebay

I think your tables could and should be more modern because of what looks to be a gray frame on your bed.