Do you have access to a kiln? If not it might be a WHILE before you’ll be using it as a table. The reason for this is because will need to properly dry out the wood before using it. You could layout the slabs in your backyard or garage but you won’t achieve the level of dryness of the lumber at HD, Loews, etc. A moisture meter for wood will help. Are you aware of drying defects too? The sapwood and heartwood will shrink at different rates which may result in surface checking and cracking.