Every spell added to a character sheet adds over a dozen attributes. Every attribute must be loaded into RAM when the campaign is loaded. This is why you can click a spell and it functions more-or-less instantly, without having to search an online database. If you loaded every spell available onto a sheet, you would be adding many hundreds of attributes that must be loaded into RAM from when you start the game. If you did this over several character, the number of attributes quickly becomes unwieldy. The solution is to run lean. Load only the spells you need at the time. It takes a little more setup time, but the playtime improvements are worth it. Analogy: Your car might hold six passengers and be able to pull a mobile home trailer. This is convenient for having what and whom you need at any time. But your performance and gas mileage will suffer.
