I have main tables and appendix tables in my paper. I would like to number the appendix tables "A1", "A2", "A3", etc OR, at the very least, re-start the table numbering at 1 in the appendix. Any suggestions on how to do that?
A slightly more robust solution than that proposed by @HeikoOberdiek is to use
\Alph to format the name of the current appendix.
For example, I have multiple appendix chapters (A, B, etc.), and otherwise have my table names formatted with a period between chapter number and table number, so the following update of
\thetable continues this convention through the appendix:
In your case, assuming the appendix is a chapter (a MWE would help), you could just use the following, without a period:
If your appendix is a section, you would want something like this: