There are lots of ways to do this.  Here's one:

'----- start of code -----
Function fncTableExists( _
       TableName As String, _
       Optional DBPath As String) _
   As Boolean

   Dim DB As DAO.Database

   If Len(DBPath) > 0 Then
       Set DB = DBEngine.OpenDatabase(DBPath)
   Else
       Set DB = CurrentDb
   End If

   If Len(TableName) = 0 Then Err.Raise 5

   On Error Resume Next
   fncTableExists = IsObject(DB.TableDefs(TableName))

   If Not DB Is Nothing Then
       DB.Close
       Set DB = Nothing
   End If

End Function

'----- end of code -----

The above function requires that you have a reference set to the
Microsoft DAO 3.x Object Library -- 3.6 for Access 2000 or later, 3.51
for Access 97.  To check for the existence of a table in the current
database, you would call it like this:

   If fncTableExists("SomeTableName") Then
       ' the table exists
   Else
       ' it doesn't
   End If

Public Function funcTableExists(strTable As String) As Boolean
On Error GoTo ErrorPoint

' This function will check to see if a
' table exists within the current database
' Similar to IsLoaded function it will return True or False
' Jeff Conrad - Access Junkie
' Usage:
' If funcTableExists("SomeTable") = True Then
'    ' Table Exists
' Else
'    ' Table does not exist
' End If
' **Requires DAO Reference be set**

   Dim db As DAO.Database
   Dim doc As DAO.Document

   Set db = CurrentDb()

   With db.Containers!Tables
       For Each doc In .Documents
           If doc.Name = strTable Then
               funcTableExists = True
           End If
       Next doc
   End With

ExitPoint:
   On Error Resume Next
   Set db = Nothing
   Exit Function

ErrorPoint:
   MsgBox "The following error has occurred:" _
   & vbNewLine & "Error Number: " & Err.Number _
   & vbNewLine & "Error Description: " & Err.Description _
   , vbExclamation, "Unexpected Error"
   Resume ExitPoint

End Function