Search Help for Instr for starters.
You can search a string for any character... Instr will find the first
occurrence.
Example: Instr(1,"William Bonner", " ") should return 8
You can then use the mid function to find the first/second parts of the name.
Resulting Example:
Create a new query based on your Table
Add the following two new columns (only at this time)
Fname: Mid([YourNamefield],1,InStr(1,[YourNameField]," ")-1)
LName: Mid([YourNameField],InStr(1,[YourNameField]," ")+1)
Test/verify
Add other columns you want in your query results
Switch query to MakeTable and run.
If you want up Update your current table, you must Add the two column names
in design view first.