I am trying to write to a single index of an array of structs containing 2 vector arrays in a save game object. I want to be able to load to memory only that single index without loading the entire variable. Is this possible? Is there a better way to load and write to an array of structs, without loading the entire variable? The reason I ask this is because the entire variable is too large to be loaded to memory without causing a memory leak.
You Load a Slot as wholw, regardless of what you need. But what of its content you store in variables after loading, remains to.you.
you can take the array of the loaded slot and from there the one index you need and store that somewhere, then dumo the rest if the slot…
But… if your savegame is to big to be handled by the memory, i would think of another way to store such values… since savegames of game progress are not meant to hold GBs of Data…
f.e.: If you eant to store an inventory of items, where each itrms is a struct in an inventory array… better create a DataTable of that struct and make your inventory only hold the Item Name ( is the Variable type) and an integer of the Quantity… so you only store an array of {Name, Integer}, which is way smaller than holding a full struct with all Datas of Items…
think of ways to shrink your Savegame filesize 
To give some more background info, I haven’t actually tried the save game object yet. I was originally just writing to new variables in a user widget blueprint, but it started to lag for minutes at a time after too many variables were added. I should only be working with about 80 vector arrays with around 1000 members at a time, so I’m not sure what is causing this lag since that shouldn’t be GBs of data. The only reason I asked about the save game object is because I read online that it might be a better solution.
would suggest you try to get your hands on some xml writer/reader code… wether you write your own one or search for plugins…
and use those for storing/loading Data Sets.